CINXE.COM
semop - Perldoc Browser
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>semop - Perldoc Browser</title> <link rel="search" href="/opensearch.xml" type="application/opensearchdescription+xml" title="Perldoc Browser"> <link rel="canonical" href="https://perldoc.perl.org/functions/semop"> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous"> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.5.0/styles/stackoverflow-light.min.css" integrity="sha512-cG1IdFxqipi3gqLmksLtuk13C+hBa57a6zpWxMeoY3Q9O6ooFxq50DayCdm0QrDgZjMUn23z/0PMZlgft7Yp5Q==" crossorigin="anonymous" /> <style> body { background: #f4f4f5; color: #020202; } .navbar-dark { background-image: -webkit-linear-gradient(top, #005f85 0, #002e49 100%); background-image: -o-linear-gradient(top, #005f85 0, #002e49 100%); background-image: linear-gradient(to bottom, #005f85 0, #002e49 100%); filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff005f85', endColorstr='#ff002e49', GradientType=0); background-repeat: repeat-x; } .navbar-dark .navbar-nav .nav-link, .navbar-dark .navbar-nav .nav-link:focus { color: #fff } .navbar-dark .navbar-nav .nav-link:hover { color: #ffef68 } #wrapperlicious { margin: 0 auto; font: 0.9em 'Helvetica Neue', Helvetica, sans-serif; font-weight: normal; line-height: 1.5em; margin: 0; padding: 0; } #wrapperlicious h1 { font-size: 1.5em } #wrapperlicious h2 { font-size: 1.3em } #wrapperlicious h3 { font-size: 1.1em } #wrapperlicious h4 { font-size: 0.9em } #wrapperlicious h1, #wrapperlicious h2, #wrapperlicious h3, #wrapperlicious h4, #wrapperlicious dt { color: #020202; margin-top: 1em; margin-bottom: 1em; position: relative; font-weight: bold; } #wrapperlicious a { color: inherit; text-decoration: underline } #wrapperlicious #toc { text-decoration: none } #wrapperlicious a:hover { color: #2a2a2a } #wrapperlicious a img { border: 0 } #wrapperlicious :not(pre) > code { color: inherit; background-color: rgba(0, 0, 0, 0.04); border-radius: 3px; font: 0.9em Consolas, Menlo, Monaco, monospace; padding: 0.3em; } #wrapperlicious dd { margin: 0; margin-left: 2em; } #wrapperlicious dt { color: #2a2a2a; font-weight: bold; margin-left: 0.9em; } #wrapperlicious p { margin-bottom: 1em; margin-top: 1em; } #wrapperlicious li > p { margin-bottom: 0; margin-top: 0; } #wrapperlicious pre { border: 1px solid #c1c1c1; border-radius: 3px; font: 100% Consolas, Menlo, Monaco, monospace; margin-bottom: 1em; margin-top: 1em; } #wrapperlicious pre > code { display: block; background-color: #f6f6f6; font: 0.9em Consolas, Menlo, Monaco, monospace; line-height: 1.5em; text-align: left; white-space: pre; padding: 1em; } #wrapperlicious dl, #wrapperlicious ol, #wrapperlicious ul { margin-bottom: 1em; margin-top: 1em; } #wrapperlicious ul { list-style-type: square; } #wrapperlicious ul ul { margin-bottom: 0px; margin-top: 0px; } #footer { font-size: 0.8em; padding-top: 0.5em; text-align: center; } #more { display: inline; font-size: 0.8em; } #perldocdiv { background-color: #fff; border: 1px solid #c1c1c1; border-bottom-left-radius: 5px; border-bottom-right-radius: 5px; margin-left: auto; margin-right: auto; padding: 3em; padding-top: 1em; max-width: 960px; } #moduleversion { float: right } #wrapperlicious .leading-notice { font-style: italic; padding-left: 1em; margin-top: 1em; margin-bottom: 1em; } #wrapperlicious .permalink { display: none; left: -0.75em; position: absolute; padding-right: 0.25em; text-decoration: none; } #wrapperlicious h1:hover .permalink, #wrapperlicious h2:hover .permalink, #wrapperlicious h3:hover .permalink, #wrapperlicious h4:hover .permalink, #wrapperlicious dt:hover .permalink { display: block; } </style> <!-- Global site tag (gtag.js) - Google Analytics --> <script async src="https://www.googletagmanager.com/gtag/js?id=G-KVNWBNT5FB"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-KVNWBNT5FB'); gtag('config', 'UA-50555-3'); </script> </head> <body> <nav class="navbar navbar-expand-md navbar-dark bg-dark justify-content-between"> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <a class="navbar-brand" href="/"><img src="/images/perl_camel_30.png" width="30" height="30" class="d-inline-block align-top" alt="Perl Camel Logo"> Perldoc Browser</a> <div class="collapse navbar-collapse" id="navbarNav"> <ul class="navbar-nav mr-auto"> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-stable" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">5.8.3</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-stable"> <a class="dropdown-item" href="/functions/semop">Latest</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.40.1/functions/semop">5.40.1</a> <a class="dropdown-item" href="/5.40.0/functions/semop">5.40.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.38.3/functions/semop">5.38.3</a> <a class="dropdown-item" href="/5.38.2/functions/semop">5.38.2</a> <a class="dropdown-item" href="/5.38.1/functions/semop">5.38.1</a> <a class="dropdown-item" href="/5.38.0/functions/semop">5.38.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.36.3/functions/semop">5.36.3</a> <a class="dropdown-item" href="/5.36.2/functions/semop">5.36.2</a> <a class="dropdown-item" href="/5.36.1/functions/semop">5.36.1</a> <a class="dropdown-item" href="/5.36.0/functions/semop">5.36.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.34.3/functions/semop">5.34.3</a> <a class="dropdown-item" href="/5.34.2/functions/semop">5.34.2</a> <a class="dropdown-item" href="/5.34.1/functions/semop">5.34.1</a> <a class="dropdown-item" href="/5.34.0/functions/semop">5.34.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.32.1/functions/semop">5.32.1</a> <a class="dropdown-item" href="/5.32.0/functions/semop">5.32.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.30.3/functions/semop">5.30.3</a> <a class="dropdown-item" href="/5.30.2/functions/semop">5.30.2</a> <a class="dropdown-item" href="/5.30.1/functions/semop">5.30.1</a> <a class="dropdown-item" href="/5.30.0/functions/semop">5.30.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.28.3/functions/semop">5.28.3</a> <a class="dropdown-item" href="/5.28.2/functions/semop">5.28.2</a> <a class="dropdown-item" href="/5.28.1/functions/semop">5.28.1</a> <a class="dropdown-item" href="/5.28.0/functions/semop">5.28.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.26.3/functions/semop">5.26.3</a> <a class="dropdown-item" href="/5.26.2/functions/semop">5.26.2</a> <a class="dropdown-item" href="/5.26.1/functions/semop">5.26.1</a> <a class="dropdown-item" href="/5.26.0/functions/semop">5.26.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.24.4/functions/semop">5.24.4</a> <a class="dropdown-item" href="/5.24.3/functions/semop">5.24.3</a> <a class="dropdown-item" href="/5.24.2/functions/semop">5.24.2</a> <a class="dropdown-item" href="/5.24.1/functions/semop">5.24.1</a> <a class="dropdown-item" href="/5.24.0/functions/semop">5.24.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.22.4/functions/semop">5.22.4</a> <a class="dropdown-item" href="/5.22.3/functions/semop">5.22.3</a> <a class="dropdown-item" href="/5.22.2/functions/semop">5.22.2</a> <a class="dropdown-item" href="/5.22.1/functions/semop">5.22.1</a> <a class="dropdown-item" href="/5.22.0/functions/semop">5.22.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.20.3/functions/semop">5.20.3</a> <a class="dropdown-item" href="/5.20.2/functions/semop">5.20.2</a> <a class="dropdown-item" href="/5.20.1/functions/semop">5.20.1</a> <a class="dropdown-item" href="/5.20.0/functions/semop">5.20.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.18.4/functions/semop">5.18.4</a> <a class="dropdown-item" href="/5.18.3/functions/semop">5.18.3</a> <a class="dropdown-item" href="/5.18.2/functions/semop">5.18.2</a> <a class="dropdown-item" href="/5.18.1/functions/semop">5.18.1</a> <a class="dropdown-item" href="/5.18.0/functions/semop">5.18.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.16.3/functions/semop">5.16.3</a> <a class="dropdown-item" href="/5.16.2/functions/semop">5.16.2</a> <a class="dropdown-item" href="/5.16.1/functions/semop">5.16.1</a> <a class="dropdown-item" href="/5.16.0/functions/semop">5.16.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.14.4/functions/semop">5.14.4</a> <a class="dropdown-item" href="/5.14.3/functions/semop">5.14.3</a> <a class="dropdown-item" href="/5.14.2/functions/semop">5.14.2</a> <a class="dropdown-item" href="/5.14.1/functions/semop">5.14.1</a> <a class="dropdown-item" href="/5.14.0/functions/semop">5.14.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.12.5/functions/semop">5.12.5</a> <a class="dropdown-item" href="/5.12.4/functions/semop">5.12.4</a> <a class="dropdown-item" href="/5.12.3/functions/semop">5.12.3</a> <a class="dropdown-item" href="/5.12.2/functions/semop">5.12.2</a> <a class="dropdown-item" href="/5.12.1/functions/semop">5.12.1</a> <a class="dropdown-item" href="/5.12.0/functions/semop">5.12.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.10.1/functions/semop">5.10.1</a> <a class="dropdown-item" href="/5.10.0/functions/semop">5.10.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.8.9/functions/semop">5.8.9</a> <a class="dropdown-item" href="/5.8.8/functions/semop">5.8.8</a> <a class="dropdown-item" href="/5.8.7/functions/semop">5.8.7</a> <a class="dropdown-item" href="/5.8.6/functions/semop">5.8.6</a> <a class="dropdown-item" href="/5.8.5/functions/semop">5.8.5</a> <a class="dropdown-item" href="/5.8.4/functions/semop">5.8.4</a> <a class="dropdown-item active" href="/5.8.3/functions/semop">5.8.3</a> <a class="dropdown-item" href="/5.8.2/functions/semop">5.8.2</a> <a class="dropdown-item" href="/5.8.1/functions/semop">5.8.1</a> <a class="dropdown-item" href="/5.8.0/functions/semop">5.8.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.6.2/functions/semop">5.6.2</a> <a class="dropdown-item" href="/5.6.1/functions/semop">5.6.1</a> <a class="dropdown-item" href="/5.6.0/functions/semop">5.6.0</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.005_04/functions/semop">5.005_04</a> <a class="dropdown-item" href="/5.005_03/functions/semop">5.005_03</a> <a class="dropdown-item" href="/5.005_02/functions/semop">5.005_02</a> <a class="dropdown-item" href="/5.005_01/functions/semop">5.005_01</a> <a class="dropdown-item" href="/5.005/functions/semop">5.005</a> </div> </li> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-dev" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dev</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-dev"> <a class="dropdown-item" href="/blead/functions/semop">blead</a> <a class="dropdown-item" href="/5.41.9/functions/semop">5.41.9</a> <a class="dropdown-item" href="/5.41.8/functions/semop">5.41.8</a> <a class="dropdown-item" href="/5.41.7/functions/semop">5.41.7</a> <a class="dropdown-item" href="/5.41.6/functions/semop">5.41.6</a> <a class="dropdown-item" href="/5.41.5/functions/semop">5.41.5</a> <a class="dropdown-item" href="/5.41.4/functions/semop">5.41.4</a> <a class="dropdown-item" href="/5.41.3/functions/semop">5.41.3</a> <a class="dropdown-item" href="/5.41.2/functions/semop">5.41.2</a> <a class="dropdown-item" href="/5.41.1/functions/semop">5.41.1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.40.1-RC1/functions/semop">5.40.1-RC1</a> <a class="dropdown-item" href="/5.40.0-RC2/functions/semop">5.40.0-RC2</a> <a class="dropdown-item" href="/5.40.0-RC1/functions/semop">5.40.0-RC1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.39.10/functions/semop">5.39.10</a> <a class="dropdown-item" href="/5.39.9/functions/semop">5.39.9</a> <a class="dropdown-item" href="/5.39.8/functions/semop">5.39.8</a> <a class="dropdown-item" href="/5.39.7/functions/semop">5.39.7</a> <a class="dropdown-item" href="/5.39.6/functions/semop">5.39.6</a> <a class="dropdown-item" href="/5.39.5/functions/semop">5.39.5</a> <a class="dropdown-item" href="/5.39.4/functions/semop">5.39.4</a> <a class="dropdown-item" href="/5.39.3/functions/semop">5.39.3</a> <a class="dropdown-item" href="/5.39.2/functions/semop">5.39.2</a> <a class="dropdown-item" href="/5.39.1/functions/semop">5.39.1</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.38.3-RC1/functions/semop">5.38.3-RC1</a> </div> </li> <li class="nav-item dropdown text-nowrap"> <a class="nav-link dropdown-toggle" href="#" id="dropdownlink-nav" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Documentation</a> <div class="dropdown-menu" aria-labelledby="dropdownlink-nav"> <a class="dropdown-item" href="/5.8.3/perl">Perl</a> <a class="dropdown-item" href="/5.8.3/perlintro">Intro</a> <a class="dropdown-item" href="/5.8.3/perl#Tutorials">Tutorials</a> <a class="dropdown-item" href="/5.8.3/perlfaq">FAQs</a> <a class="dropdown-item" href="/5.8.3/perl#Reference-Manual">Reference</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.8.3/perlop">Operators</a> <a class="dropdown-item" href="/5.8.3/functions">Functions</a> <a class="dropdown-item" href="/5.8.3/variables">Variables</a> <a class="dropdown-item" href="/5.8.3/modules">Modules</a> <a class="dropdown-item" href="/5.8.3/perlutil">Utilities</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="/5.8.3/perldelta">Release Notes</a> <a class="dropdown-item" href="/5.8.3/perlcommunity">Community</a> <a class="dropdown-item" href="/5.8.3/perlhist">History</a> </div> </li> </ul> <ul class="navbar-nav"> <script> function set_expand (expand) { var perldocdiv = document.getElementById('perldocdiv'); var width = window.getComputedStyle(perldocdiv).getPropertyValue('max-width'); var expanded = (width == '' || width == 'none') ? true : false; if (expand === null) { expand = !expanded; } if ((expand && !expanded) || (!expand && expanded)) { perldocdiv.style.setProperty('max-width', expand ? 'none' : '960px'); var button_classlist = document.getElementById('content-expand-button').classList; if (expand) { button_classlist.add('btn-light'); button_classlist.remove('btn-outline-light'); } else { button_classlist.add('btn-outline-light'); button_classlist.remove('btn-light'); } } return expand; } function toggle_expand () { var expand = set_expand(null); document.cookie = 'perldoc_expand=' + (expand ? 1 : 0) + '; path=/; expires=Tue, 19 Jan 2038 03:14:07 UTC'; } function read_expand () { return document.cookie.split(';').some(function (item) { return item.indexOf('perldoc_expand=1') >= 0 }); } if (document.readyState === 'loading') { document.addEventListener('DOMContentLoaded', function () { if (read_expand()) { set_expand(true); } }); } else if (read_expand()) { set_expand(true); } </script> <button id="content-expand-button" type="button" class="btn btn-outline-light d-none d-lg-inline-block mr-4" onclick="toggle_expand()">Expand</button> </ul> <form class="form-inline" method="get" action="/5.8.3/search"> <input class="form-control mr-3" type="search" name="q" placeholder="Search" aria-label="Search" value=""> </form> </div> </nav> <div id="wrapperlicious" class="container-fluid"> <div id="perldocdiv"> <div id="links"> <a href="/5.8.3/functions">functions</a> / <a href="/5.8.3/functions/semop">semop</a> <div id="more"> (<a href="/5.8.3/functions/semop.txt">source</a>, <a href="https://metacpan.org/pod/perlfunc#semop-KEY,OPSTRING">CPAN</a>) </div> </div> <div class="leading-notice"> You are viewing the version of this documentation from Perl 5.8.3. <a href="/functions/semop">View the latest version</a> </div> <dl> <dt id="semop-KEY,OPSTRING"><a class="permalink" href="#semop-KEY,OPSTRING">#</a><a id="semop"></a><a id="semop-KEY-OPSTRING"></a>semop KEY,OPSTRING</dt> <dd> <p>Calls the System V IPC function semop to perform semaphore operations such as signalling and waiting. OPSTRING must be a packed array of semop structures. Each semop structure can be generated with <code>pack("s!3", $semnum, $semop, $semflag)</code>. The number of semaphore operations is implied by the length of OPSTRING. Returns true if successful, or false if there is an error. As an example, the following code waits on semaphore $semnum of semaphore id $semid:</p> <pre><code>$semop = pack("s!3", $semnum, -1, 0); die "Semaphore trouble: $!\n" unless semop($semid, $semop);</code></pre> <p>To signal the semaphore, replace <code>-1</code> with <code>1</code>. See also <a href="/5.8.3/perlipc#SysV-IPC">"SysV IPC" in perlipc</a>, <code>IPC::SysV</code>, and <code>IPC::SysV::Semaphore</code> documentation.</p> </dd> </dl> </div> <div id="footer"> <p>Perldoc Browser is maintained by Dan Book (<a href="https://metacpan.org/author/DBOOK">DBOOK</a>). Please contact him via the <a href="https://github.com/Grinnz/perldoc-browser/issues">GitHub issue tracker</a> or <a href="mailto:dbook@cpan.org">email</a> regarding any issues with the site itself, search, or rendering of documentation.</p> <p>The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via the <a href="https://github.com/Perl/perl5/issues">Perl issue tracker</a>, the <a href="https://lists.perl.org/list/perl5-porters.html">mailing list</a>, or <a href="https://kiwiirc.com/client/irc.perl.org/p5p">IRC</a> to report any issues with the contents or format of the documentation.</p> </div> </div> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.slim.min.js" integrity="sha512-/DXTXr6nQodMUiq+IUJYCt2PPOUjrHJ9wFrqpJ3XkgPNOZVfMok7cRw6CSxyCQxXn6ozlESsSh1/sMCTF1rL/g==" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.1/umd/popper.min.js" integrity="sha512-ubuT8Z88WxezgSqf3RLuNi5lmjstiJcyezx34yIU2gAHonIi27Na7atqzUZCOoY4CExaoFumzOsFQ2Ch+I/HCw==" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script> <script src="/js/highlight.pack.js"></script> <script>hljs.highlightAll();</script> </body> </html>