File: C:/Ruby27-x64/share/doc/ruby/html/Open3.html
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<h3>Methods</h3>
<ul class="link-list" role="directory">
<li ><a href="#method-c-capture2">::capture2</a>
<li ><a href="#method-c-capture2e">::capture2e</a>
<li ><a href="#method-c-capture3">::capture3</a>
<li ><a href="#method-c-pipeline">::pipeline</a>
<li ><a href="#method-c-pipeline_r">::pipeline_r</a>
<li ><a href="#method-c-pipeline_rw">::pipeline_rw</a>
<li ><a href="#method-c-pipeline_start">::pipeline_start</a>
<li ><a href="#method-c-pipeline_w">::pipeline_w</a>
<li ><a href="#method-c-popen2">::popen2</a>
<li ><a href="#method-c-popen2e">::popen2e</a>
<li ><a href="#method-c-popen3">::popen3</a>
<li ><a href="#method-i-capture2">#capture2</a>
<li ><a href="#method-i-capture2e">#capture2e</a>
<li ><a href="#method-i-capture3">#capture3</a>
<li ><a href="#method-i-pipeline">#pipeline</a>
<li ><a href="#method-i-pipeline_r">#pipeline_r</a>
<li ><a href="#method-i-pipeline_rw">#pipeline_rw</a>
<li ><a href="#method-i-pipeline_start">#pipeline_start</a>
<li ><a href="#method-i-pipeline_w">#pipeline_w</a>
<li ><a href="#method-i-popen2">#popen2</a>
<li ><a href="#method-i-popen2e">#popen2e</a>
<li ><a href="#method-i-popen3">#popen3</a>
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<h1 id="module-Open3" class="module">
module Open3
</h1>
<section class="description">
<p><a href="Open3.html"><code>Open3</code></a> grants you access to stdin, stdout, stderr and a thread to wait for the child process when running another program. You can specify various attributes, redirections, current directory, etc., of the program in the same way as for <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<ul><li>
<p><a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> : pipes for stdin, stdout, stderr</p>
</li><li>
<p><a href="Open3.html#method-c-popen2"><code>Open3.popen2</code></a> : pipes for stdin, stdout</p>
</li><li>
<p><a href="Open3.html#method-c-popen2e"><code>Open3.popen2e</code></a> : pipes for stdin, merged stdout and stderr</p>
</li><li>
<p><a href="Open3.html#method-c-capture3"><code>Open3.capture3</code></a> : give a string for stdin; get strings for stdout, stderr</p>
</li><li>
<p><a href="Open3.html#method-c-capture2"><code>Open3.capture2</code></a> : give a string for stdin; get a string for stdout</p>
</li><li>
<p><a href="Open3.html#method-c-capture2e"><code>Open3.capture2e</code></a> : give a string for stdin; get a string for merged stdout and stderr</p>
</li><li>
<p><a href="Open3.html#method-c-pipeline_rw"><code>Open3.pipeline_rw</code></a> : pipes for first stdin and last stdout of a pipeline</p>
</li><li>
<p><a href="Open3.html#method-c-pipeline_r"><code>Open3.pipeline_r</code></a> : pipe for last stdout of a pipeline</p>
</li><li>
<p><a href="Open3.html#method-c-pipeline_w"><code>Open3.pipeline_w</code></a> : pipe for first stdin of a pipeline</p>
</li><li>
<p><a href="Open3.html#method-c-pipeline_start"><code>Open3.pipeline_start</code></a> : run a pipeline without waiting</p>
</li><li>
<p><a href="Open3.html#method-c-pipeline"><code>Open3.pipeline</code></a> : run a pipeline and wait for its completion</p>
</li></ul>
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section id="public-class-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Public Class Methods</h3>
</header>
<div id="method-c-capture2" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture2</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture2"><code>Open3.capture2</code></a> captures the standard output of a command.</p>
<pre>stdout_str, status = Open3.capture2([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># factor is a command for integer factorization.</span>
<span class="ruby-identifier">o</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2</span>(<span class="ruby-string">"factor"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-string">"42"</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span> <span class="ruby-comment">#=> "42: 2 3 7\n"</span>
<span class="ruby-comment"># generate x**2 graph in png using gnuplot.</span>
<span class="ruby-identifier">gnuplot_commands</span> = <span class="ruby-identifier"><<"End"</span>
<span class="ruby-value"> set terminal png
plot x**2, "-" with lines
1 14
2 1
3 8
4 5
e
</span><span class="ruby-identifier">End</span>
<span class="ruby-identifier">image</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2</span>(<span class="ruby-string">"gnuplot"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">gnuplot_commands</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
</pre>
<div class="method-source-code" id="capture2-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 332</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>)
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">o</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">out_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-capture2e" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture2e</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture2e"><code>Open3.capture2e</code></a> captures the standard output and the standard error of a command.</p>
<pre>stdout_and_stderr_str, status = Open3.capture2e([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># capture make log</span>
<span class="ruby-identifier">make_log</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2e</span>(<span class="ruby-string">"make"</span>)
</pre>
<div class="method-source-code" id="capture2e-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 380</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>)
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">oe</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">oe</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">outerr_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">oe</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">outerr_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-capture3" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture3</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture3"><code>Open3.capture3</code></a> captures the standard output and the standard error of a command.</p>
<pre>stdout_str, stderr_str, status = Open3.capture3([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Examples:</p>
<pre class="ruby"><span class="ruby-comment"># dot is a command of graphviz.</span>
<span class="ruby-identifier">graph</span> = <span class="ruby-identifier"><<'End'</span>
<span class="ruby-value"> digraph g {
a -> b
}
</span><span class="ruby-identifier">End</span>
<span class="ruby-identifier">drawn_graph</span>, <span class="ruby-identifier">dot_log</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"dot -v"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">graph</span>)
<span class="ruby-identifier">o</span>, <span class="ruby-identifier">e</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"echo abc; sort >&2"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-string">"foo\nbar\nbaz\n"</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span> <span class="ruby-comment">#=> "abc\n"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">e</span> <span class="ruby-comment">#=> "bar\nbaz\nfoo\n"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">s</span> <span class="ruby-comment">#=> #<Process::Status: pid 32682 exit 0></span>
<span class="ruby-comment"># generate a thumbnail image using the convert command of ImageMagick.</span>
<span class="ruby-comment"># However, if the image is really stored in a file,</span>
<span class="ruby-comment"># system("convert", "-thumbnail", "80", "png:#{filename}", "png:-") is better</span>
<span class="ruby-comment"># because of reduced memory consumption.</span>
<span class="ruby-comment"># But if the image is stored in a DB or generated by the gnuplot Open3.capture2 example,</span>
<span class="ruby-comment"># Open3.capture3 should be considered.</span>
<span class="ruby-comment">#</span>
<span class="ruby-identifier">image</span> = <span class="ruby-constant">File</span>.<span class="ruby-identifier">read</span>(<span class="ruby-string">"/usr/share/openclipart/png/animals/mammals/sheep-md-v0.1.png"</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
<span class="ruby-identifier">thumbnail</span>, <span class="ruby-identifier">err</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"convert -thumbnail 80 png:- png:-"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">image</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
<span class="ruby-keyword">if</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">success?</span>
<span class="ruby-constant">STDOUT</span>.<span class="ruby-identifier">binmode</span>; <span class="ruby-identifier">print</span> <span class="ruby-identifier">thumbnail</span>
<span class="ruby-keyword">end</span>
</pre>
<div class="method-source-code" id="capture3-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 271</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>) <span class="ruby-operator">||</span> <span class="ruby-string">''</span>
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">e</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">o</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">e</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-identifier">err_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">e</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">out_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">err_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pipeline" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline</span><span
class="method-args">(*cmds)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline"><code>Open3.pipeline</code></a> starts a list of commands as a pipeline. It waits for the completion of the commands. No pipes are created for stdin of the first command and stdout of the last command.</p>
<pre>status_list = Open3.pipeline(cmd1, cmd2, ... [, opts])</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-identifier">fname</span> = <span class="ruby-string">"/usr/share/man/man1/ruby.1.gz"</span>
<span class="ruby-identifier">p</span> <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"zcat"</span>, <span class="ruby-identifier">fname</span>], <span class="ruby-string">"nroff -man"</span>, <span class="ruby-string">"less"</span>)
<span class="ruby-comment">#=> [#<Process::Status: pid 11817 exit 0>,</span>
<span class="ruby-comment"># #<Process::Status: pid 11820 exit 0>,</span>
<span class="ruby-comment"># #<Process::Status: pid 11828 exit 0>]</span>
<span class="ruby-identifier">fname</span> = <span class="ruby-string">"/usr/share/man/man1/ls.1.gz"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"zcat"</span>, <span class="ruby-identifier">fname</span>], <span class="ruby-string">"nroff -man"</span>, <span class="ruby-string">"colcrt"</span>)
<span class="ruby-comment"># convert PDF to PS and send to a printer by lpr</span>
<span class="ruby-identifier">pdf_file</span> = <span class="ruby-string">"paper.pdf"</span>
<span class="ruby-identifier">printer</span> = <span class="ruby-string">"printer-name"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"pdftops"</span>, <span class="ruby-identifier">pdf_file</span>, <span class="ruby-string">"-"</span>],
[<span class="ruby-string">"lpr"</span>, <span class="ruby-node">"-P#{printer}"</span>])
<span class="ruby-comment"># count lines</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>(<span class="ruby-string">"sort"</span>, <span class="ruby-string">"uniq -c"</span>, <span class="ruby-value">:in</span><span class="ruby-operator">=></span><span class="ruby-string">"names.txt"</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-string">"count"</span>)
<span class="ruby-comment"># cyclic pipeline</span>
<span class="ruby-identifier">r</span>,<span class="ruby-identifier">w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">w</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"ibase=14\n10\n"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>(<span class="ruby-string">"bc"</span>, <span class="ruby-string">"tee /dev/tty"</span>, <span class="ruby-value">:in</span><span class="ruby-operator">=></span><span class="ruby-identifier">r</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-identifier">w</span>)
<span class="ruby-comment">#=> 14</span>
<span class="ruby-comment"># 18</span>
<span class="ruby-comment"># 22</span>
<span class="ruby-comment"># 30</span>
<span class="ruby-comment"># 42</span>
<span class="ruby-comment"># 58</span>
<span class="ruby-comment"># 78</span>
<span class="ruby-comment"># 106</span>
<span class="ruby-comment"># 202</span>
</pre>
<div class="method-source-code" id="pipeline-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 679</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], []) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">ts</span>.<span class="ruby-identifier">map</span>(<span class="ruby-operator">&</span><span class="ruby-value">:value</span>)
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pipeline_r" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_r</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_r"><code>Open3.pipeline_r</code></a> starts a list of commands as a pipeline with a pipe which connects to stdout of the last command.</p>
<pre>Open3.pipeline_r(cmd1, cmd2, ... [, opts]) {|last_stdout, wait_threads|
...
}
last_stdout, wait_threads = Open3.pipeline_r(cmd1, cmd2, ... [, opts])
...
last_stdout.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre>Open3.pipeline_r("zcat /var/log/apache2/access.log.*.gz",
[{"LANG"=>"C"}, "grep", "GET /favicon.ico"],
"logresolve") {|o, ts|
o.each_line {|line|
...
}
}
Open3.pipeline_r("yes", "head -10") {|o, ts|
p o.read #=> "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"
p ts[0].value #=> #<Process::Status: pid 24910 SIGPIPE (signal 13)>
p ts[1].value #=> #<Process::Status: pid 24913 exit 0>
}</pre>
<div class="method-source-code" id="pipeline_r-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 510</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_r</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pipeline_rw" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_rw</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_rw"><code>Open3.pipeline_rw</code></a> starts a list of commands as a pipeline with pipes which connect to stdin of the first command and stdout of the last command.</p>
<pre>Open3.pipeline_rw(cmd1, cmd2, ... [, opts]) {|first_stdin, last_stdout, wait_threads|
...
}
first_stdin, last_stdout, wait_threads = Open3.pipeline_rw(cmd1, cmd2, ... [, opts])
...
first_stdin.close
last_stdout.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>The options to pass to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> are constructed by merging <code>opts</code>, the last hash element of the array, and specifications for the pipes between each of the commands.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_rw</span>(<span class="ruby-string">"tr -dc A-Za-z"</span>, <span class="ruby-string">"wc -c"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"All persons more than a mile high to leave the court."</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_rw</span>(<span class="ruby-string">"sort"</span>, <span class="ruby-string">"cat -n"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">stdin</span>, <span class="ruby-identifier">stdout</span>, <span class="ruby-identifier">wait_thrs</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"foo"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"bar"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"baz"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">close</span> <span class="ruby-comment"># send EOF to sort.</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">stdout</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment">#=> " 1\tbar\n 2\tbaz\n 3\tfoo\n"</span>
}
</pre>
<div class="method-source-code" id="pipeline_rw-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 454</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_rw</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pipeline_start" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_start</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_start"><code>Open3.pipeline_start</code></a> starts a list of commands as a pipeline. No pipes are created for stdin of the first command and stdout of the last command.</p>
<pre>Open3.pipeline_start(cmd1, cmd2, ... [, opts]) {|wait_threads|
...
}
wait_threads = Open3.pipeline_start(cmd1, cmd2, ... [, opts])
...</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># Run xeyes in 10 seconds.</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_start</span>(<span class="ruby-string">"xeyes"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">sleep</span> <span class="ruby-value">10</span>
<span class="ruby-identifier">t</span> = <span class="ruby-identifier">ts</span>[<span class="ruby-value">0</span>]
<span class="ruby-constant">Process</span>.<span class="ruby-identifier">kill</span>(<span class="ruby-string">"TERM"</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">pid</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span> <span class="ruby-comment">#=> #<Process::Status: pid 911 SIGTERM (signal 15)></span>
}
<span class="ruby-comment"># Convert pdf to ps and send it to a printer.</span>
<span class="ruby-comment"># Collect error message of pdftops and lpr.</span>
<span class="ruby-identifier">pdf_file</span> = <span class="ruby-string">"paper.pdf"</span>
<span class="ruby-identifier">printer</span> = <span class="ruby-string">"printer-name"</span>
<span class="ruby-identifier">err_r</span>, <span class="ruby-identifier">err_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_start</span>([<span class="ruby-string">"pdftops"</span>, <span class="ruby-identifier">pdf_file</span>, <span class="ruby-string">"-"</span>],
[<span class="ruby-string">"lpr"</span>, <span class="ruby-node">"-P#{printer}"</span>],
<span class="ruby-value">:err</span><span class="ruby-operator">=></span><span class="ruby-identifier">err_w</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">err_w</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">err_r</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment"># error messages of pdftops and lpr.</span>
}
</pre>
<div class="method-source-code" id="pipeline_start-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 611</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_start</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">block</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], [], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">ts</span>, = <span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], [])
<span class="ruby-identifier">ts</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-pipeline_w" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_w</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_w"><code>Open3.pipeline_w</code></a> starts a list of commands as a pipeline with a pipe which connects to stdin of the first command.</p>
<pre>Open3.pipeline_w(cmd1, cmd2, ... [, opts]) {|first_stdin, wait_threads|
...
}
first_stdin, wait_threads = Open3.pipeline_w(cmd1, cmd2, ... [, opts])
...
first_stdin.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_w</span>(<span class="ruby-string">"bzip2 -c"</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-string">"/tmp/hello.bz2"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"hello"</span>
}
</pre>
<div class="method-source-code" id="pipeline_w-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 552</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_w</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>], [<span class="ruby-identifier">in_w</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-popen2" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen2</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-popen2"><code>Open3.popen2</code></a> is similar to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except that it doesn't create a pipe for the standard error stream.</p>
<p>Block form:</p>
<pre>Open3.popen2([env,] cmd... [, opts]) {|stdin, stdout, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout, wait_thr = Open3.popen2([env,] cmd... [, opts])
...
stdin.close # stdin and stdout should be closed explicitly in this form.
stdout.close</pre>
<p>See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> for the optional hash arguments <em>env</em> and <em>opts</em>.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"wc -c"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"answer to life the universe and everything"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"bc -q"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"obase=13"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"6 * 9"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"dc"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"42P"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment">#=> "*"</span>
}
</pre>
<div class="method-source-code" id="popen2-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 145</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-popen2e" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen2e</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-popen2e"><code>Open3.popen2e</code></a> is similar to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except that it merges the standard output stream and the standard error stream.</p>
<p>Block form:</p>
<pre>Open3.popen2e([env,] cmd... [, opts]) {|stdin, stdout_and_stderr, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout_and_stderr, wait_thr = Open3.popen2e([env,] cmd... [, opts])
...
stdin.close # stdin and stdout_and_stderr should be closed explicitly in this form.
stdout_and_stderr.close</pre>
<p>See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> for the optional hash arguments <em>env</em> and <em>opts</em>.</p>
<p>Example:</p>
<pre># check gcc warnings
source = "foo.c"
Open3.popen2e("gcc", "-Wall", source) {|i,oe,t|
oe.each {|line|
if /warning/ =~ line
...
end
}
}</pre>
<div class="method-source-code" id="popen2e-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 194</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[[<span class="ruby-value">:out</span>, <span class="ruby-value">:err</span>]] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-c-popen3" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen3</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Open stdin, stdout, and stderr streams and start external executable. In addition, a thread to wait for the started process is created. The thread has a pid method and a thread variable :pid which is the pid of the started process.</p>
<p>Block form:</p>
<pre>Open3.popen3([env,] cmd... [, opts]) {|stdin, stdout, stderr, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout, stderr, wait_thr = Open3.popen3([env,] cmd... [, opts])
pid = wait_thr[:pid] # pid of the started process
...
stdin.close # stdin, stdout and stderr should be closed explicitly in this form.
stdout.close
stderr.close
exit_status = wait_thr.value # Process::Status object returned.</pre>
<p>The parameters env, cmd, and opts are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>. A commandline string and a list of argument strings can be accepted as follows:</p>
<pre>Open3.popen3("echo abc") {|i, o, e, t| ... }
Open3.popen3("echo", "abc") {|i, o, e, t| ... }
Open3.popen3(["echo", "argv0"], "abc") {|i, o, e, t| ... }</pre>
<p>If the last parameter, opts, is a <a href="Hash.html"><code>Hash</code></a>, it is recognized as an option for <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen3</span>(<span class="ruby-string">"pwd"</span>, <span class="ruby-value">:chdir</span><span class="ruby-operator">=></span><span class="ruby-string">"/"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">e</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span>.<span class="ruby-identifier">chomp</span> <span class="ruby-comment">#=> "/"</span>
}
</pre>
<p>wait_thr.value waits for the termination of the process. The block form also waits for the process when it returns.</p>
<p>Closing stdin, stdout and stderr does not wait for the process to complete.</p>
<p>You should be careful to avoid deadlocks. Since pipes are fixed length buffers, <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a>(“prog”) {|i, o, e, t| o.read } deadlocks if the program generates too much output on stderr. You should read stdout and stderr simultaneously (using threads or <a href="IO.html#method-c-select"><code>IO.select</code></a>). However, if you don't need stderr output, you can use <a href="Open3.html#method-c-popen2"><code>Open3.popen2</code></a>. If merged stdout and stderr output is not a problem, you can use <a href="Open3.html#method-c-popen2e"><code>Open3.popen2e</code></a>. If you really need stdout and stderr output as separate strings, you can consider <a href="Open3.html#method-c-capture3"><code>Open3.capture3</code></a>.</p>
<div class="method-source-code" id="popen3-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 84</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">err_r</span>, <span class="ruby-identifier">err_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:err</span>] = <span class="ruby-identifier">err_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>, <span class="ruby-identifier">err_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">err_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
</section>
<section id="private-instance-5Buntitled-5D-method-details" class="method-section">
<header>
<h3>Private Instance Methods</h3>
</header>
<div id="method-i-capture2" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture2</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture2"><code>Open3.capture2</code></a> captures the standard output of a command.</p>
<pre>stdout_str, status = Open3.capture2([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># factor is a command for integer factorization.</span>
<span class="ruby-identifier">o</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2</span>(<span class="ruby-string">"factor"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-string">"42"</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span> <span class="ruby-comment">#=> "42: 2 3 7\n"</span>
<span class="ruby-comment"># generate x**2 graph in png using gnuplot.</span>
<span class="ruby-identifier">gnuplot_commands</span> = <span class="ruby-identifier"><<"End"</span>
<span class="ruby-value"> set terminal png
plot x**2, "-" with lines
1 14
2 1
3 8
4 5
e
</span><span class="ruby-identifier">End</span>
<span class="ruby-identifier">image</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2</span>(<span class="ruby-string">"gnuplot"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">gnuplot_commands</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
</pre>
<div class="method-source-code" id="capture2-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 332</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>)
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">o</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">out_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-capture2e" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture2e</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture2e"><code>Open3.capture2e</code></a> captures the standard output and the standard error of a command.</p>
<pre>stdout_and_stderr_str, status = Open3.capture2e([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># capture make log</span>
<span class="ruby-identifier">make_log</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture2e</span>(<span class="ruby-string">"make"</span>)
</pre>
<div class="method-source-code" id="capture2e-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 380</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>)
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">oe</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">oe</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">outerr_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">oe</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">outerr_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-capture3" class="method-detail ">
<div class="method-heading">
<span class="method-name">capture3</span><span
class="method-args">(*cmd)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-capture3"><code>Open3.capture3</code></a> captures the standard output and the standard error of a command.</p>
<pre>stdout_str, stderr_str, status = Open3.capture3([env,] cmd... [, opts])</pre>
<p>The arguments env, cmd and opts are passed to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except <code>opts[:stdin_data]</code> and <code>opts[:binmode]</code>. See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<p>If <code>opts[:stdin_data]</code> is specified, it is sent to the command's standard input.</p>
<p>If <code>opts[:binmode]</code> is true, internal pipes are set to binary mode.</p>
<p>Examples:</p>
<pre class="ruby"><span class="ruby-comment"># dot is a command of graphviz.</span>
<span class="ruby-identifier">graph</span> = <span class="ruby-identifier"><<'End'</span>
<span class="ruby-value"> digraph g {
a -> b
}
</span><span class="ruby-identifier">End</span>
<span class="ruby-identifier">drawn_graph</span>, <span class="ruby-identifier">dot_log</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"dot -v"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">graph</span>)
<span class="ruby-identifier">o</span>, <span class="ruby-identifier">e</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"echo abc; sort >&2"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-string">"foo\nbar\nbaz\n"</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span> <span class="ruby-comment">#=> "abc\n"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">e</span> <span class="ruby-comment">#=> "bar\nbaz\nfoo\n"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">s</span> <span class="ruby-comment">#=> #<Process::Status: pid 32682 exit 0></span>
<span class="ruby-comment"># generate a thumbnail image using the convert command of ImageMagick.</span>
<span class="ruby-comment"># However, if the image is really stored in a file,</span>
<span class="ruby-comment"># system("convert", "-thumbnail", "80", "png:#{filename}", "png:-") is better</span>
<span class="ruby-comment"># because of reduced memory consumption.</span>
<span class="ruby-comment"># But if the image is stored in a DB or generated by the gnuplot Open3.capture2 example,</span>
<span class="ruby-comment"># Open3.capture3 should be considered.</span>
<span class="ruby-comment">#</span>
<span class="ruby-identifier">image</span> = <span class="ruby-constant">File</span>.<span class="ruby-identifier">read</span>(<span class="ruby-string">"/usr/share/openclipart/png/animals/mammals/sheep-md-v0.1.png"</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
<span class="ruby-identifier">thumbnail</span>, <span class="ruby-identifier">err</span>, <span class="ruby-identifier">s</span> = <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">capture3</span>(<span class="ruby-string">"convert -thumbnail 80 png:- png:-"</span>, <span class="ruby-value">:stdin_data</span><span class="ruby-operator">=></span><span class="ruby-identifier">image</span>, <span class="ruby-value">:binmode</span><span class="ruby-operator">=></span><span class="ruby-keyword">true</span>)
<span class="ruby-keyword">if</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">success?</span>
<span class="ruby-constant">STDOUT</span>.<span class="ruby-identifier">binmode</span>; <span class="ruby-identifier">print</span> <span class="ruby-identifier">thumbnail</span>
<span class="ruby-keyword">end</span>
</pre>
<div class="method-source-code" id="capture3-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 271</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">capture3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">stdin_data</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:stdin_data</span>) <span class="ruby-operator">||</span> <span class="ruby-string">''</span>
<span class="ruby-identifier">binmode</span> = <span class="ruby-identifier">opts</span>.<span class="ruby-identifier">delete</span>(<span class="ruby-value">:binmode</span>)
<span class="ruby-identifier">popen3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">e</span>, <span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">o</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-identifier">e</span>.<span class="ruby-identifier">binmode</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-identifier">err_reader</span> = <span class="ruby-constant">Thread</span>.<span class="ruby-identifier">new</span> { <span class="ruby-identifier">e</span>.<span class="ruby-identifier">read</span> }
<span class="ruby-keyword">begin</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">stdin_data</span>.<span class="ruby-identifier">respond_to?</span> <span class="ruby-value">:readpartial</span>
<span class="ruby-constant">IO</span>.<span class="ruby-identifier">copy_stream</span>(<span class="ruby-identifier">stdin_data</span>, <span class="ruby-identifier">i</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">write</span> <span class="ruby-identifier">stdin_data</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">rescue</span> <span class="ruby-constant">Errno</span><span class="ruby-operator">::</span><span class="ruby-constant">EPIPE</span>
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
[<span class="ruby-identifier">out_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">err_reader</span>.<span class="ruby-identifier">value</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span>]
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-pipeline" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline</span><span
class="method-args">(*cmds)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline"><code>Open3.pipeline</code></a> starts a list of commands as a pipeline. It waits for the completion of the commands. No pipes are created for stdin of the first command and stdout of the last command.</p>
<pre>status_list = Open3.pipeline(cmd1, cmd2, ... [, opts])</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-identifier">fname</span> = <span class="ruby-string">"/usr/share/man/man1/ruby.1.gz"</span>
<span class="ruby-identifier">p</span> <span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"zcat"</span>, <span class="ruby-identifier">fname</span>], <span class="ruby-string">"nroff -man"</span>, <span class="ruby-string">"less"</span>)
<span class="ruby-comment">#=> [#<Process::Status: pid 11817 exit 0>,</span>
<span class="ruby-comment"># #<Process::Status: pid 11820 exit 0>,</span>
<span class="ruby-comment"># #<Process::Status: pid 11828 exit 0>]</span>
<span class="ruby-identifier">fname</span> = <span class="ruby-string">"/usr/share/man/man1/ls.1.gz"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"zcat"</span>, <span class="ruby-identifier">fname</span>], <span class="ruby-string">"nroff -man"</span>, <span class="ruby-string">"colcrt"</span>)
<span class="ruby-comment"># convert PDF to PS and send to a printer by lpr</span>
<span class="ruby-identifier">pdf_file</span> = <span class="ruby-string">"paper.pdf"</span>
<span class="ruby-identifier">printer</span> = <span class="ruby-string">"printer-name"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>([<span class="ruby-string">"pdftops"</span>, <span class="ruby-identifier">pdf_file</span>, <span class="ruby-string">"-"</span>],
[<span class="ruby-string">"lpr"</span>, <span class="ruby-node">"-P#{printer}"</span>])
<span class="ruby-comment"># count lines</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>(<span class="ruby-string">"sort"</span>, <span class="ruby-string">"uniq -c"</span>, <span class="ruby-value">:in</span><span class="ruby-operator">=></span><span class="ruby-string">"names.txt"</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-string">"count"</span>)
<span class="ruby-comment"># cyclic pipeline</span>
<span class="ruby-identifier">r</span>,<span class="ruby-identifier">w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">w</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"ibase=14\n10\n"</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline</span>(<span class="ruby-string">"bc"</span>, <span class="ruby-string">"tee /dev/tty"</span>, <span class="ruby-value">:in</span><span class="ruby-operator">=></span><span class="ruby-identifier">r</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-identifier">w</span>)
<span class="ruby-comment">#=> 14</span>
<span class="ruby-comment"># 18</span>
<span class="ruby-comment"># 22</span>
<span class="ruby-comment"># 30</span>
<span class="ruby-comment"># 42</span>
<span class="ruby-comment"># 58</span>
<span class="ruby-comment"># 78</span>
<span class="ruby-comment"># 106</span>
<span class="ruby-comment"># 202</span>
</pre>
<div class="method-source-code" id="pipeline-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 679</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], []) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">ts</span>.<span class="ruby-identifier">map</span>(<span class="ruby-operator">&</span><span class="ruby-value">:value</span>)
}
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-pipeline_r" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_r</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_r"><code>Open3.pipeline_r</code></a> starts a list of commands as a pipeline with a pipe which connects to stdout of the last command.</p>
<pre>Open3.pipeline_r(cmd1, cmd2, ... [, opts]) {|last_stdout, wait_threads|
...
}
last_stdout, wait_threads = Open3.pipeline_r(cmd1, cmd2, ... [, opts])
...
last_stdout.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre>Open3.pipeline_r("zcat /var/log/apache2/access.log.*.gz",
[{"LANG"=>"C"}, "grep", "GET /favicon.ico"],
"logresolve") {|o, ts|
o.each_line {|line|
...
}
}
Open3.pipeline_r("yes", "head -10") {|o, ts|
p o.read #=> "y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n"
p ts[0].value #=> #<Process::Status: pid 24910 SIGPIPE (signal 13)>
p ts[1].value #=> #<Process::Status: pid 24913 exit 0>
}</pre>
<div class="method-source-code" id="pipeline_r-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 510</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_r</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-pipeline_rw" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_rw</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_rw"><code>Open3.pipeline_rw</code></a> starts a list of commands as a pipeline with pipes which connect to stdin of the first command and stdout of the last command.</p>
<pre>Open3.pipeline_rw(cmd1, cmd2, ... [, opts]) {|first_stdin, last_stdout, wait_threads|
...
}
first_stdin, last_stdout, wait_threads = Open3.pipeline_rw(cmd1, cmd2, ... [, opts])
...
first_stdin.close
last_stdout.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>The options to pass to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> are constructed by merging <code>opts</code>, the last hash element of the array, and specifications for the pipes between each of the commands.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_rw</span>(<span class="ruby-string">"tr -dc A-Za-z"</span>, <span class="ruby-string">"wc -c"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">o</span>, <span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"All persons more than a mile high to leave the court."</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_rw</span>(<span class="ruby-string">"sort"</span>, <span class="ruby-string">"cat -n"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">stdin</span>, <span class="ruby-identifier">stdout</span>, <span class="ruby-identifier">wait_thrs</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"foo"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"bar"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"baz"</span>
<span class="ruby-identifier">stdin</span>.<span class="ruby-identifier">close</span> <span class="ruby-comment"># send EOF to sort.</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">stdout</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment">#=> " 1\tbar\n 2\tbaz\n 3\tfoo\n"</span>
}
</pre>
<div class="method-source-code" id="pipeline_rw-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 454</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_rw</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-pipeline_start" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_start</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_start"><code>Open3.pipeline_start</code></a> starts a list of commands as a pipeline. No pipes are created for stdin of the first command and stdout of the last command.</p>
<pre>Open3.pipeline_start(cmd1, cmd2, ... [, opts]) {|wait_threads|
...
}
wait_threads = Open3.pipeline_start(cmd1, cmd2, ... [, opts])
...</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-comment"># Run xeyes in 10 seconds.</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_start</span>(<span class="ruby-string">"xeyes"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">sleep</span> <span class="ruby-value">10</span>
<span class="ruby-identifier">t</span> = <span class="ruby-identifier">ts</span>[<span class="ruby-value">0</span>]
<span class="ruby-constant">Process</span>.<span class="ruby-identifier">kill</span>(<span class="ruby-string">"TERM"</span>, <span class="ruby-identifier">t</span>.<span class="ruby-identifier">pid</span>)
<span class="ruby-identifier">p</span> <span class="ruby-identifier">t</span>.<span class="ruby-identifier">value</span> <span class="ruby-comment">#=> #<Process::Status: pid 911 SIGTERM (signal 15)></span>
}
<span class="ruby-comment"># Convert pdf to ps and send it to a printer.</span>
<span class="ruby-comment"># Collect error message of pdftops and lpr.</span>
<span class="ruby-identifier">pdf_file</span> = <span class="ruby-string">"paper.pdf"</span>
<span class="ruby-identifier">printer</span> = <span class="ruby-string">"printer-name"</span>
<span class="ruby-identifier">err_r</span>, <span class="ruby-identifier">err_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_start</span>([<span class="ruby-string">"pdftops"</span>, <span class="ruby-identifier">pdf_file</span>, <span class="ruby-string">"-"</span>],
[<span class="ruby-string">"lpr"</span>, <span class="ruby-node">"-P#{printer}"</span>],
<span class="ruby-value">:err</span><span class="ruby-operator">=></span><span class="ruby-identifier">err_w</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">err_w</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">err_r</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment"># error messages of pdftops and lpr.</span>
}
</pre>
<div class="method-source-code" id="pipeline_start-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 611</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_start</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">if</span> <span class="ruby-identifier">block</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], [], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">ts</span>, = <span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [], [])
<span class="ruby-identifier">ts</span>
<span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-pipeline_w" class="method-detail ">
<div class="method-heading">
<span class="method-name">pipeline_w</span><span
class="method-args">(*cmds, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-pipeline_w"><code>Open3.pipeline_w</code></a> starts a list of commands as a pipeline with a pipe which connects to stdin of the first command.</p>
<pre>Open3.pipeline_w(cmd1, cmd2, ... [, opts]) {|first_stdin, wait_threads|
...
}
first_stdin, wait_threads = Open3.pipeline_w(cmd1, cmd2, ... [, opts])
...
first_stdin.close</pre>
<p>Each cmd is a string or an array. If it is an array, the elements are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre>cmd:
commandline command line string which is passed to a shell
[env, commandline, opts] command line string which is passed to a shell
[env, cmdname, arg1, ..., opts] command name and one or more arguments (no shell)
[env, [cmdname, argv0], arg1, ..., opts] command name and arguments including argv[0] (no shell)
Note that env and opts are optional, as for Process.spawn.</pre>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">pipeline_w</span>(<span class="ruby-string">"bzip2 -c"</span>, <span class="ruby-value">:out</span><span class="ruby-operator">=></span><span class="ruby-string">"/tmp/hello.bz2"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>, <span class="ruby-identifier">ts</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"hello"</span>
}
</pre>
<div class="method-source-code" id="pipeline_w-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 552</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">pipeline_w</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmds</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmds</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">pipeline_run</span>(<span class="ruby-identifier">cmds</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>], [<span class="ruby-identifier">in_w</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-popen2" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen2</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-popen2"><code>Open3.popen2</code></a> is similar to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except that it doesn't create a pipe for the standard error stream.</p>
<p>Block form:</p>
<pre>Open3.popen2([env,] cmd... [, opts]) {|stdin, stdout, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout, wait_thr = Open3.popen2([env,] cmd... [, opts])
...
stdin.close # stdin and stdout should be closed explicitly in this form.
stdout.close</pre>
<p>See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> for the optional hash arguments <em>env</em> and <em>opts</em>.</p>
<p>Example:</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"wc -c"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"answer to life the universe and everything"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"bc -q"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"obase=13"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">puts</span> <span class="ruby-string">"6 * 9"</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">gets</span> <span class="ruby-comment">#=> "42\n"</span>
}
<span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen2</span>(<span class="ruby-string">"dc"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">print</span> <span class="ruby-string">"42P"</span>
<span class="ruby-identifier">i</span>.<span class="ruby-identifier">close</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span> <span class="ruby-comment">#=> "*"</span>
}
</pre>
<div class="method-source-code" id="popen2-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 145</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen2</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-popen2e" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen2e</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p><a href="Open3.html#method-c-popen2e"><code>Open3.popen2e</code></a> is similar to <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a> except that it merges the standard output stream and the standard error stream.</p>
<p>Block form:</p>
<pre>Open3.popen2e([env,] cmd... [, opts]) {|stdin, stdout_and_stderr, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout_and_stderr, wait_thr = Open3.popen2e([env,] cmd... [, opts])
...
stdin.close # stdin and stdout_and_stderr should be closed explicitly in this form.
stdout_and_stderr.close</pre>
<p>See <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a> for the optional hash arguments <em>env</em> and <em>opts</em>.</p>
<p>Example:</p>
<pre># check gcc warnings
source = "foo.c"
Open3.popen2e("gcc", "-Wall", source) {|i,oe,t|
oe.each {|line|
if /warning/ =~ line
...
end
}
}</pre>
<div class="method-source-code" id="popen2e-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 194</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen2e</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[[<span class="ruby-value">:out</span>, <span class="ruby-value">:err</span>]] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
<div id="method-i-popen3" class="method-detail ">
<div class="method-heading">
<span class="method-name">popen3</span><span
class="method-args">(*cmd, &block)</span>
<span class="method-click-advice">click to toggle source</span>
</div>
<div class="method-description">
<p>Open stdin, stdout, and stderr streams and start external executable. In addition, a thread to wait for the started process is created. The thread has a pid method and a thread variable :pid which is the pid of the started process.</p>
<p>Block form:</p>
<pre>Open3.popen3([env,] cmd... [, opts]) {|stdin, stdout, stderr, wait_thr|
pid = wait_thr.pid # pid of the started process.
...
exit_status = wait_thr.value # Process::Status object returned.
}</pre>
<p>Non-block form:</p>
<pre>stdin, stdout, stderr, wait_thr = Open3.popen3([env,] cmd... [, opts])
pid = wait_thr[:pid] # pid of the started process
...
stdin.close # stdin, stdout and stderr should be closed explicitly in this form.
stdout.close
stderr.close
exit_status = wait_thr.value # Process::Status object returned.</pre>
<p>The parameters env, cmd, and opts are passed to <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>. A commandline string and a list of argument strings can be accepted as follows:</p>
<pre>Open3.popen3("echo abc") {|i, o, e, t| ... }
Open3.popen3("echo", "abc") {|i, o, e, t| ... }
Open3.popen3(["echo", "argv0"], "abc") {|i, o, e, t| ... }</pre>
<p>If the last parameter, opts, is a <a href="Hash.html"><code>Hash</code></a>, it is recognized as an option for <a href="Process.html#method-c-spawn"><code>Process.spawn</code></a>.</p>
<pre class="ruby"><span class="ruby-constant">Open3</span>.<span class="ruby-identifier">popen3</span>(<span class="ruby-string">"pwd"</span>, <span class="ruby-value">:chdir</span><span class="ruby-operator">=></span><span class="ruby-string">"/"</span>) {<span class="ruby-operator">|</span><span class="ruby-identifier">i</span>,<span class="ruby-identifier">o</span>,<span class="ruby-identifier">e</span>,<span class="ruby-identifier">t</span><span class="ruby-operator">|</span>
<span class="ruby-identifier">p</span> <span class="ruby-identifier">o</span>.<span class="ruby-identifier">read</span>.<span class="ruby-identifier">chomp</span> <span class="ruby-comment">#=> "/"</span>
}
</pre>
<p>wait_thr.value waits for the termination of the process. The block form also waits for the process when it returns.</p>
<p>Closing stdin, stdout and stderr does not wait for the process to complete.</p>
<p>You should be careful to avoid deadlocks. Since pipes are fixed length buffers, <a href="Open3.html#method-c-popen3"><code>Open3.popen3</code></a>(“prog”) {|i, o, e, t| o.read } deadlocks if the program generates too much output on stderr. You should read stdout and stderr simultaneously (using threads or <a href="IO.html#method-c-select"><code>IO.select</code></a>). However, if you don't need stderr output, you can use <a href="Open3.html#method-c-popen2"><code>Open3.popen2</code></a>. If merged stdout and stderr output is not a problem, you can use <a href="Open3.html#method-c-popen2e"><code>Open3.popen2e</code></a>. If you really need stdout and stderr output as separate strings, you can consider <a href="Open3.html#method-c-capture3"><code>Open3.capture3</code></a>.</p>
<div class="method-source-code" id="popen3-source">
<pre><span class="ruby-comment"># File lib/open3.rb, line 84</span>
<span class="ruby-keyword">def</span> <span class="ruby-identifier ruby-title">popen3</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">cmd</span>, <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">if</span> <span class="ruby-constant">Hash</span> <span class="ruby-operator">===</span> <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">last</span>
<span class="ruby-identifier">opts</span> = <span class="ruby-identifier">cmd</span>.<span class="ruby-identifier">pop</span>.<span class="ruby-identifier">dup</span>
<span class="ruby-keyword">else</span>
<span class="ruby-identifier">opts</span> = {}
<span class="ruby-keyword">end</span>
<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">in_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:in</span>] = <span class="ruby-identifier">in_r</span>
<span class="ruby-identifier">in_w</span>.<span class="ruby-identifier">sync</span> = <span class="ruby-keyword">true</span>
<span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">out_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:out</span>] = <span class="ruby-identifier">out_w</span>
<span class="ruby-identifier">err_r</span>, <span class="ruby-identifier">err_w</span> = <span class="ruby-constant">IO</span>.<span class="ruby-identifier">pipe</span>
<span class="ruby-identifier">opts</span>[<span class="ruby-value">:err</span>] = <span class="ruby-identifier">err_w</span>
<span class="ruby-identifier">popen_run</span>(<span class="ruby-identifier">cmd</span>, <span class="ruby-identifier">opts</span>, [<span class="ruby-identifier">in_r</span>, <span class="ruby-identifier">out_w</span>, <span class="ruby-identifier">err_w</span>], [<span class="ruby-identifier">in_w</span>, <span class="ruby-identifier">out_r</span>, <span class="ruby-identifier">err_r</span>], <span class="ruby-operator">&</span><span class="ruby-identifier">block</span>)
<span class="ruby-keyword">end</span></pre>
</div>
</div>
</div>
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</section>
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