mirror of
https://github.com/rawiriblundell/wiki.bash-hackers.org
synced 2024-11-02 00:53:07 +01:00
621 lines
35 KiB
Plaintext
621 lines
35 KiB
Plaintext
<!DOCTYPE html>
|
|
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" dir="ltr" class="no-js">
|
|
<head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=TPXmWR5s" charset="utf-8"></script>
|
|
<script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script>
|
|
<script type="text/javascript">
|
|
__wm.init("http://web.archive.org/web");
|
|
__wm.wombat("https://wiki.bash-hackers.org/howto/calculate-dc?do=edit","20220615023700","http://web.archive.org/","web","/_static/",
|
|
"1655260620");
|
|
</script>
|
|
<link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" />
|
|
<link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=qtvMKcIJ" />
|
|
<!-- End Wayback Rewrite JS Include -->
|
|
|
|
<meta charset="UTF-8"/>
|
|
<title>Calculating with dc [Bash Hackers Wiki]</title>
|
|
<script>(function(H){H.className=H.className.replace(/\bno-js\b/,'js')})(document.documentElement)</script>
|
|
<meta name="viewport" content="width=device-width,initial-scale=1"/>
|
|
<link rel="shortcut icon" href="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/images/favicon.ico"/>
|
|
<link rel="apple-touch-icon" href="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/images/apple-touch-icon.png"/>
|
|
<meta name="generator" content="DokuWiki"/>
|
|
<meta name="robots" content="noindex,nofollow"/>
|
|
<link type="text/css" rel="stylesheet" href="/web/20220615023700cs_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/bootstrap/default/bootstrap.min.css"/>
|
|
<link rel="search" type="application/opensearchdescription+xml" href="/web/20220615023700/https://wiki.bash-hackers.org/lib/exe/opensearch.php" title="Bash Hackers Wiki"/>
|
|
<link rel="start" href="/"/>
|
|
<link rel="contents" href="/howto/calculate-dc?do=index" title="Sitemap"/>
|
|
<link rel="manifest" href="/web/20220615023700/https://wiki.bash-hackers.org/lib/exe/manifest.php"/>
|
|
<link rel="alternate" type="application/rss+xml" title="Recent Changes" href="/web/20220615023700/https://wiki.bash-hackers.org/feed.php"/>
|
|
<link rel="alternate" type="application/rss+xml" title="Current namespace" href="/web/20220615023700/https://wiki.bash-hackers.org/feed.php?mode=list&ns=howto"/>
|
|
<link rel="alternate" type="text/html" title="Plain HTML" href="/web/20220615023700/https://wiki.bash-hackers.org/_export/xhtml/howto/calculate-dc"/>
|
|
<link rel="alternate" type="text/plain" title="Wiki Markup" href="/web/20220615023700/https://wiki.bash-hackers.org/_export/raw/howto/calculate-dc"/>
|
|
<link rel="stylesheet" type="text/css" href="/web/20220615023700cs_/https://wiki.bash-hackers.org/lib/exe/css.php?t=bootstrap3&tseed=54923c3deda180f2db5bd755cd8fbf1a"/>
|
|
<!--[if gte IE 9]><!-->
|
|
<script type="text/javascript">/*<![CDATA[*/var NS='howto';var JSINFO = {"updatable":1,"userreplace":1,"default_macro_string":"","plugins":{"edittable":{"default columnwidth":""}},"move_renameokay":false,"isadmin":0,"isauth":0,"bootstrap3":{"mode":"source","toc":[],"config":{"collapsibleSections":0,"fixedTopNavbar":1,"showSemanticPopup":0,"sidebarOnNavbar":0,"tagsOnTop":1,"tocAffix":1,"tocCollapseOnScroll":1,"tocCollapsed":0,"tocLayout":"default","useAnchorJS":1,"useAlternativeToolbarIcons":1}},"id":"howto:calculate-dc","namespace":"howto","ACT":"source","useHeadingNavigation":1,"useHeadingContent":1};
|
|
/*!]]>*/</script>
|
|
<script type="text/javascript" charset="utf-8" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/exe/jquery.php?tseed=23f888679b4f1dc26eef34902aca964f"></script>
|
|
<script type="text/javascript" charset="utf-8" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/exe/js.php?t=bootstrap3&tseed=54923c3deda180f2db5bd755cd8fbf1a"></script>
|
|
<script type="text/javascript">/*<![CDATA[*/if (typeof IconifyConfig == 'undefined') { var IconifyConfig = { 'defaultAPI' : '/lib/tpl/bootstrap3/iconify.php?prefix={prefix}&icons={icons}' } }
|
|
/*!]]>*/</script>
|
|
<script type="text/javascript" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/bootstrap/js/bootstrap.min.js"></script>
|
|
<script type="text/javascript" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/anchorjs/anchor.min.js"></script>
|
|
<script type="text/javascript" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/typeahead/bootstrap3-typeahead.min.js"></script>
|
|
<script type="text/javascript" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/iconify/iconify.min.js"></script>
|
|
<script type="text/javascript" src="/web/20220615023700js_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/assets/iconify/plugins/fa.js"></script>
|
|
<!--<![endif]-->
|
|
<style type="text/css">@media screen { body { margin-top: 65px; } #dw__toc.affix { top: 55px; position: fixed !important; } #dw__toc .nav .nav .nav { display: none; } }</style>
|
|
<!--[if lt IE 9]>
|
|
<script type="text/javascript" src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
|
|
<script type="text/javascript" src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
|
|
<![endif]-->
|
|
</head>
|
|
<body class="default dokuwiki mode_source tpl_bootstrap3 dw-page-on-panel dw-fluid-container" data-page-id="howto:calculate-dc"><div class="dokuwiki">
|
|
<header id="dokuwiki__header" class="dw-container dokuwiki container-fluid mx-5">
|
|
<!-- navbar -->
|
|
<nav id="dw__navbar" class="navbar navbar-fixed-top navbar-default" role="navigation">
|
|
|
|
<div class="dw-container container-fluid mx-5">
|
|
|
|
<div class="navbar-header">
|
|
|
|
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navbar-collapse">
|
|
<span class="icon-bar"></span>
|
|
<span class="icon-bar"></span>
|
|
<span class="icon-bar"></span>
|
|
</button>
|
|
|
|
<a class="navbar-brand d-flex align-items-center" href="/web/20220615023700/https://wiki.bash-hackers.org/start" accesskey="h" title="Bash Hackers Wiki"><img id="dw__logo" class="pull-left h-100 mr-4" alt="Bash Hackers Wiki" src="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/images/logo.png"/><div class="pull-right"><div id="dw__title">Bash Hackers Wiki</div></div></a>
|
|
</div>
|
|
|
|
<div class="collapse navbar-collapse">
|
|
|
|
|
|
|
|
|
|
<div class="navbar-right" id="dw__navbar_items">
|
|
|
|
|
|
<!-- navbar-searchform -->
|
|
<form action="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc" accept-charset="utf-8" class="navbar-form navbar-left search" id="dw__search" method="get" role="search">
|
|
<div class="input-group">
|
|
<input id="qsearch" autocomplete="off" type="search" placeholder="Search" value="" accesskey="f" name="q" class="form-control" title="[F]"/>
|
|
<div class="input-group-btn">
|
|
<button class="btn btn-default" type="submit" title="Search">
|
|
<span class="iconify" data-icon="mdi:magnify"></span> </button>
|
|
</div>
|
|
|
|
</div>
|
|
<input type="hidden" name="do" value="search"/>
|
|
</form>
|
|
<!-- /navbar-searchform -->
|
|
<!-- tools-menu -->
|
|
<ul class="nav navbar-nav dw-action-icon" id="dw__tools">
|
|
|
|
|
|
<li class="dropdown">
|
|
|
|
<a href="" class="dropdown-toggle" data-target="#" data-toggle="dropdown" title="" role="button" aria-haspopup="true" aria-expanded="false">
|
|
<span class="iconify" data-icon="mdi:wrench"></span> <span class="hidden-lg hidden-md hidden-sm">Tools</span> <span class="caret"></span>
|
|
</a>
|
|
|
|
<ul class="dropdown-menu tools" role="menu">
|
|
|
|
<li class="dropdown-header">
|
|
<span class="iconify" data-icon="mdi:account"></span> User Tools </li>
|
|
|
|
<li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=register" title="Register" rel="nofollow" class="menuitem register"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M15 14c-2.67 0-8 1.33-8 4v2h16v-2c0-2.67-5.33-4-8-4m-9-4V7H4v3H1v2h3v3h2v-3h3v-2m6 2a4 4 0 0 0 4-4 4 4 0 0 0-4-4 4 4 0 0 0-4 4 4 4 0 0 0 4 4z"/></svg><span>Register</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=login&sectok=" title="Log In" rel="nofollow" class="menuitem login"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M10 17.25V14H3v-4h7V6.75L15.25 12 10 17.25M8 2h9a2 2 0 0 1 2 2v16a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2v-4h2v4h9V4H8v4H6V4a2 2 0 0 1 2-2z"/></svg><span>Log In</span></a></li>
|
|
<li class="divider" role="separator"></li>
|
|
|
|
|
|
<li class="dropdown-header">
|
|
<span class="iconify" data-icon="mdi:toolbox"></span> Site Tools </li>
|
|
|
|
<li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=recent" title="Recent Changes [r]" rel="nofollow" accesskey="r" class="menuitem recent"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M15 13h1.5v2.82l2.44 1.41-.75 1.3L15 16.69V13m4-5H5v11h4.67c-.43-.91-.67-1.93-.67-3a7 7 0 0 1 7-7c1.07 0 2.09.24 3 .67V8M5 21a2 2 0 0 1-2-2V5c0-1.11.89-2 2-2h1V1h2v2h8V1h2v2h1a2 2 0 0 1 2 2v6.1c1.24 1.26 2 2.99 2 4.9a7 7 0 0 1-7 7c-1.91 0-3.64-.76-4.9-2H5m11-9.85A4.85 4.85 0 0 0 11.15 16c0 2.68 2.17 4.85 4.85 4.85A4.85 4.85 0 0 0 20.85 16c0-2.68-2.17-4.85-4.85-4.85z"/></svg><span>Recent Changes</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=media&ns=howto" title="Media Manager" rel="nofollow" class="menuitem media"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M7 15l4.5-6 3.5 4.5 2.5-3L21 15m1-11h-8l-2-2H6a2 2 0 0 0-2 2v12a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2V6a2 2 0 0 0-2-2M2 6H0v14a2 2 0 0 0 2 2h18v-2H2V6z"/></svg><span>Media Manager</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=index" title="Sitemap [x]" rel="nofollow" accesskey="x" class="menuitem index"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M3 3h6v4H3V3m12 7h6v4h-6v-4m0 7h6v4h-6v-4m-2-4H7v5h6v2H5V9h2v2h6v2z"/></svg><span>Sitemap</span></a></li>
|
|
<li class="divider" role="separator"></li>
|
|
|
|
|
|
<li class="dropdown-header">
|
|
<span class="iconify" data-icon="mdi:file-document-outline"></span> Page Tools </li>
|
|
|
|
<li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=" title="Show page [v]" rel="nofollow" accesskey="v" class="menuitem show"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M13 9h5.5L13 3.5V9M6 2h8l6 6v12a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V4c0-1.11.89-2 2-2m9 16v-2H6v2h9m3-4v-2H6v2h12z"/></svg><span>Show page</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=revisions" title="Old revisions [o]" rel="nofollow" accesskey="o" class="menuitem revs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M11 7v5.11l4.71 2.79.79-1.28-4-2.37V7m0-5C8.97 2 5.91 3.92 4.27 6.77L2 4.5V11h6.5L5.75 8.25C6.96 5.73 9.5 4 12.5 4a7.5 7.5 0 0 1 7.5 7.5 7.5 7.5 0 0 1-7.5 7.5c-3.27 0-6.03-2.09-7.06-5h-2.1c1.1 4.03 4.77 7 9.16 7 5.24 0 9.5-4.25 9.5-9.5A9.5 9.5 0 0 0 12.5 2z"/></svg><span>Old revisions</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=backlink" title="Backlinks" rel="nofollow" class="menuitem backlink"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M10.59 13.41c.41.39.41 1.03 0 1.42-.39.39-1.03.39-1.42 0a5.003 5.003 0 0 1 0-7.07l3.54-3.54a5.003 5.003 0 0 1 7.07 0 5.003 5.003 0 0 1 0 7.07l-1.49 1.49c.01-.82-.12-1.64-.4-2.42l.47-.48a2.982 2.982 0 0 0 0-4.24 2.982 2.982 0 0 0-4.24 0l-3.53 3.53a2.982 2.982 0 0 0 0 4.24m2.82-4.24c.39-.39 1.03-.39 1.42 0a5.003 5.003 0 0 1 0 7.07l-3.54 3.54a5.003 5.003 0 0 1-7.07 0 5.003 5.003 0 0 1 0-7.07l1.49-1.49c-.01.82.12 1.64.4 2.43l-.47.47a2.982 2.982 0 0 0 0 4.24 2.982 2.982 0 0 0 4.24 0l3.53-3.53a2.982 2.982 0 0 0 0-4.24.973.973 0 0 1 0-1.42z"/></svg><span>Backlinks</span></a></li><li class="action"><a href="#dokuwiki__top" title="Back to top [t]" rel="nofollow" accesskey="t" class="menuitem top"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8v12z"/></svg><span>Back to top</span></a></li>
|
|
|
|
</ul>
|
|
</li>
|
|
|
|
|
|
</ul>
|
|
<!-- /tools-menu -->
|
|
|
|
<ul class="nav navbar-nav">
|
|
|
|
|
|
<li>
|
|
<span class="dw__actions dw-action-icon">
|
|
<a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=register" title="Register" rel="nofollow" class="menuitem register btn btn-success navbar-btn"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M15 14c-2.67 0-8 1.33-8 4v2h16v-2c0-2.67-5.33-4-8-4m-9-4V7H4v3H1v2h3v3h2v-3h3v-2m6 2a4 4 0 0 0 4-4 4 4 0 0 0-4-4 4 4 0 0 0-4 4 4 4 0 0 0 4 4z"/></svg><span class=""> Register</span></a><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=login&sectok=" title="Log In" rel="nofollow" class="menuitem login btn btn-default navbar-btn"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M10 17.25V14H3v-4h7V6.75L15.25 12 10 17.25M8 2h9a2 2 0 0 1 2 2v16a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2v-4h2v4h9V4H8v4H6V4a2 2 0 0 1 2-2z"/></svg><span class=""> Log In</span></a> </span>
|
|
</li>
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
</div>
|
|
</div>
|
|
</nav>
|
|
<!-- navbar -->
|
|
<div align="center">
|
|
<script async src="//web.archive.org/web/20220615023700js_/https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
|
|
<!-- BHORG_BOTTOM -->
|
|
<ins class="adsbygoogle" style="display:inline-block;width:728px;height:90px" data-ad-client="ca-pub-4658830517838678" data-ad-slot="1603598940"></ins>
|
|
<script>
|
|
(adsbygoogle = window.adsbygoogle || []).push({});
|
|
</script>
|
|
</div>
|
|
|
|
</header>
|
|
|
|
<a name="dokuwiki__top" id="dokuwiki__top"></a>
|
|
|
|
<main role="main" class="dw-container pb-5 dokuwiki container-fluid mx-5">
|
|
|
|
<div id="dokuwiki__pageheader">
|
|
|
|
|
|
<!-- breadcrumbs -->
|
|
<nav id="dw__breadcrumbs" class="small">
|
|
|
|
<hr/>
|
|
|
|
<div class="dw__youarehere">
|
|
<ol class="breadcrumb" itemscope itemtype="http://schema.org/BreadcrumbList"><li>You are here</li><li itemprop="itemListElement" itemscope itemtype="http://schema.org/ListItem"><a href="/web/20220615023700/https://wiki.bash-hackers.org/start" itemprop="item" title="start"><span itemprop="name"><span class="iconify" data-icon="mdi:home"></span></span></a></li><li itemprop="itemListElement" itemscope itemtype="http://schema.org/ListItem"><a itemprop="item" href="/web/20220615023700/https://wiki.bash-hackers.org/howto/start" class="wikilink1" title="howto:start">HOWTO</a></li><li class="active" itemprop="itemListElement" itemscope itemtype="http://schema.org/ListItem"><span itemprop="name"><a itemprop="item" href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc" class="wikilink1" title="howto:calculate-dc">Calculating with dc</a></span></li></ol> </div>
|
|
|
|
<div class="dw__breadcrumbs hidden-print">
|
|
<ol class="breadcrumb"><li>Trace</li><li><a href="/web/20220615023700/https://wiki.bash-hackers.org/commands/start" title="commands:start">Commands</a></li><li><a href="/web/20220615023700/https://wiki.bash-hackers.org/commands/builtin/start" title="commands:builtin:start">Builtin Commands</a></li><li><a href="/web/20220615023700/https://wiki.bash-hackers.org/commands/builtin/caller" title="commands:builtin:caller">The caller builtin command</a></li><li><a href="/web/20220615023700/https://wiki.bash-hackers.org/commands/builtin/export" title="commands:builtin:export">The export builtin command</a></li><li><a href="/web/20220615023700/https://wiki.bash-hackers.org/commands/builtin/exit" title="commands:builtin:exit">The exit builtin command</a></li><li class="active"><a href="/web/20220615023700/https://wiki.bash-hackers.org/dict/terms/exit_status" title="dict:terms:exit_status">Exit Status</a></li></ol> </div>
|
|
|
|
<hr/>
|
|
|
|
</nav>
|
|
<!-- /breadcrumbs -->
|
|
|
|
<p class="text-right">
|
|
<span class="pageId ml-1 label label-primary">howto:calculate-dc</span> </p>
|
|
|
|
<div id="dw__msgarea" class="small">
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<div class="row">
|
|
|
|
|
|
<article id="dokuwiki__content" class="col-sm-12 col-md-12 " itemscope itemtype="http://schema.org/Article" itemref="dw__license">
|
|
|
|
|
|
<!-- page-tools -->
|
|
<nav id="dw__pagetools" class="hidden-print">
|
|
<div class="tools panel panel-default">
|
|
<ul class="nav nav-stacked nav-pills text-muted">
|
|
<li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=" title="Show page [v]" rel="nofollow" accesskey="v" class="menuitem show"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M13 9h5.5L13 3.5V9M6 2h8l6 6v12a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V4c0-1.11.89-2 2-2m9 16v-2H6v2h9m3-4v-2H6v2h12z"/></svg><span>Show page</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=revisions" title="Old revisions [o]" rel="nofollow" accesskey="o" class="menuitem revs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M11 7v5.11l4.71 2.79.79-1.28-4-2.37V7m0-5C8.97 2 5.91 3.92 4.27 6.77L2 4.5V11h6.5L5.75 8.25C6.96 5.73 9.5 4 12.5 4a7.5 7.5 0 0 1 7.5 7.5 7.5 7.5 0 0 1-7.5 7.5c-3.27 0-6.03-2.09-7.06-5h-2.1c1.1 4.03 4.77 7 9.16 7 5.24 0 9.5-4.25 9.5-9.5A9.5 9.5 0 0 0 12.5 2z"/></svg><span>Old revisions</span></a></li><li class="action"><a href="/web/20220615023700/https://wiki.bash-hackers.org/howto/calculate-dc?do=backlink" title="Backlinks" rel="nofollow" class="menuitem backlink"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M10.59 13.41c.41.39.41 1.03 0 1.42-.39.39-1.03.39-1.42 0a5.003 5.003 0 0 1 0-7.07l3.54-3.54a5.003 5.003 0 0 1 7.07 0 5.003 5.003 0 0 1 0 7.07l-1.49 1.49c.01-.82-.12-1.64-.4-2.42l.47-.48a2.982 2.982 0 0 0 0-4.24 2.982 2.982 0 0 0-4.24 0l-3.53 3.53a2.982 2.982 0 0 0 0 4.24m2.82-4.24c.39-.39 1.03-.39 1.42 0a5.003 5.003 0 0 1 0 7.07l-3.54 3.54a5.003 5.003 0 0 1-7.07 0 5.003 5.003 0 0 1 0-7.07l1.49-1.49c-.01.82.12 1.64.4 2.43l-.47.47a2.982 2.982 0 0 0 0 4.24 2.982 2.982 0 0 0 4.24 0l3.53-3.53a2.982 2.982 0 0 0 0-4.24.973.973 0 0 1 0-1.42z"/></svg><span>Backlinks</span></a></li><li class="action"><a href="#dokuwiki__top" title="Back to top [t]" rel="nofollow" accesskey="t" class="menuitem top"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewbox="0 0 24 24"><path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8v12z"/></svg><span>Back to top</span></a></li> </ul>
|
|
</div>
|
|
</nav>
|
|
<!-- /page-tools -->
|
|
|
|
<div class="panel panel-default px-3 py-2" itemprop="articleBody">
|
|
<div class="page panel-body">
|
|
|
|
|
|
<div class="dw-content-page "><!-- content --><div class="dw-content"><p>
|
|
This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
|
|
</p>
|
|
<div class="editBox" role="application">
|
|
|
|
<div class="toolbar group">
|
|
<div id="draft__status" class="draft__status"></div>
|
|
<div id="tool__bar" class="tool__bar"></div>
|
|
</div>
|
|
<form id="dw__editform" method="post" action="" accept-charset="utf-8" class=" form-inline"><div class="no">
|
|
<input type="hidden" name="sectok" value=""/><input type="hidden" name="id" value="howto:calculate-dc"/><input type="hidden" name="rev" value="0"/><input type="hidden" name="date" value="0"/><input type="hidden" name="prefix" value="."/><input type="hidden" name="suffix" value=""/><input type="hidden" name="changecheck" value="e7daf488331bf9af020089d89a6dee5e"/><input type="hidden" name="target" value="section"/><textarea name="wikitext" id="wiki__text" dir="auto" class="edit form-control" cols="80" rows="10" tabindex="1" readonly="readonly">
|
|
====== Calculating with dc ======
|
|
|
|
{{keywords>bash shell scripting arithmetic calculate}}
|
|
|
|
===== Introduction =====
|
|
|
|
dc(1) is a non standard, but commonly found, reverse-polish Desk
|
|
Calculator. According to Ken Thompson, "dc is the oldest language on
|
|
Unix; it was written on the PDP-7 and ported to the PDP-11 before Unix
|
|
[itself] was ported".
|
|
|
|
Historically the standard bc(1) has been implemented as a //front-end to dc//.
|
|
|
|
===== Simple calculation =====
|
|
|
|
In brief, the //reverse polish notation// means the numbers are put
|
|
on the stack first, then an operation is applied to them. Instead
|
|
of writing ''1+1'', you write ''1 1+''.
|
|
|
|
By default ''dc'', unlike ''bc'', doesn't print anything, the result is pushed on the stack.
|
|
You have to use the "p" command to print the element at the top of the stack.
|
|
Thus a simple operation looks like:
|
|
|
|
<code>
|
|
$ dc <<< '1 1+pq'
|
|
2
|
|
</code>
|
|
I used a "here string" present in bash 3.x, ksh93 and zsh. if your
|
|
shell doesn't support this, you can use ''echo '1 1+p' | dc'' or if you have GNU ''dc'', you can use ''dc -e '1 1 +p'''.
|
|
|
|
Of course, you can also just run ''dc'' and enter the commands.
|
|
|
|
The classic operations are:
|
|
* addition: ''+''
|
|
* subtraction: ''-''
|
|
* division: ''/''
|
|
* multiplication: ''*''
|
|
* remainder (modulo): ''%''
|
|
* exponentiation: ''^''
|
|
* square root: ''v''
|
|
GNU ''dc'' adds a couple more.
|
|
|
|
To input a negative number you need to use the ''_'' (underscore) character:
|
|
<code>
|
|
$ dc <<< '1_1-p'
|
|
2
|
|
</code>
|
|
|
|
You can use the //digits// ''0'' to ''9'' and the //letters// ''A'' to ''F'' as numbers, and a dot (''.'') as a decimal point.
|
|
The ''A'' to ''F'' **must** be capital letters in order not to be confused with the commands specified with lower case characters.
|
|
A number with a letter is considered hexadecimal:
|
|
<code>
|
|
dc <<< 'Ap'
|
|
10
|
|
</code>
|
|
The **output** is converted to **base 10** by default
|
|
|
|
===== Scale And Base =====
|
|
|
|
''dc'' is a calulator with abitrary precision, by default this precision is 0.
|
|
thus ''<nowiki>dc <<< "5 4/p"</nowiki>'' prints "1".
|
|
|
|
We can increase the precision using the ''k'' command. It pops the value at the top of the stack
|
|
and uses it as the precision argument:
|
|
<code>
|
|
dc <<< '2k5 4/p' # prints 1.25
|
|
dc <<< '4k5 4/p' # prints 1.2500
|
|
dc <<< '100k 2vp'
|
|
1.4142135623730950488016887242096980785696718753769480731766797379907\
|
|
324784621070388503875343276415727
|
|
</code>
|
|
dc supports //large// precision arguments.
|
|
|
|
You can change the base used to output (//print//) the numbers with ''o'' and the base used to
|
|
input (//type//) the numbers with ''i'':
|
|
<code>
|
|
dc << EOF
|
|
20 p# prints 20, output is in base 10
|
|
16o # the output is now in base 2 16
|
|
20p # prints 14, in hex
|
|
16i # the output is now in hex
|
|
p # prints 14 this doesn't modify the number in the stack
|
|
10p # prints 10 the output is done in base 16
|
|
EOF
|
|
</code>
|
|
|
|
Note: when the input value is modified, the base is modified for all commands, including ''i'':
|
|
|
|
<code>
|
|
dc << EOF
|
|
16i 16o # base is 16 for input and output
|
|
10p # prints 10
|
|
10i # ! set the base to 10 i.e. to 16 decimal
|
|
17p # prints 17
|
|
EOF
|
|
</code>
|
|
|
|
This code prints 17 while we might think that ''10i'' reverts the base back to 10 and thus the number should be converted to hex and printed as 11.
|
|
The problem is 10 was typed while the input base 16, thus the base was set to 10 hexadecimal, i.e. 16 decimal.
|
|
|
|
<code>
|
|
dc << EOF
|
|
16o16o10p #prints 10
|
|
Ai # set the base to A in hex i.e. 10
|
|
17p # prints 11 in base 16
|
|
EOF
|
|
</code>
|
|
|
|
===== Stack =====
|
|
|
|
There are two basic commands to manipulate the stack:
|
|
* ''d'' duplicates the top of the stack
|
|
* ''c'' clears the stack
|
|
|
|
<code>
|
|
$ dc << EOF
|
|
2 # put 2 on the stack
|
|
d # duplicate i.e. put another 2 on the stack
|
|
*p # multiply and print
|
|
c p # clear and print
|
|
EOF
|
|
4
|
|
dc: stack empty
|
|
</code>
|
|
|
|
''c p'' results in an error, as we would expect, as c removes everything
|
|
on the stack. //Note: we can use ''#'' to put comments in the script.//
|
|
|
|
If you are lost, you can inspect (i.e. print) the stack using the command
|
|
''f''. The stack remains unchanged:
|
|
|
|
<code>
|
|
dc <<< '1 2 d 4+f'
|
|
6
|
|
2
|
|
1
|
|
</code>
|
|
|
|
Note how the first element that will be popped from the stack is printed first, if you are
|
|
used to an HP calculator, it's the reverse.
|
|
|
|
Don't hesitate to put ''f'' in the examples of this tutorial, it doesn't change the result,
|
|
and it's a good way to see what's going on.
|
|
|
|
===== Registers =====
|
|
|
|
The GNU ''dc'' manual says that dc has at least **256 registers** depending on
|
|
the range of unsigned char. I'm not sure how you are supposed to use
|
|
the NUL byte.
|
|
Using a register is easy:
|
|
|
|
<code>
|
|
dc <<EOF
|
|
12 # put 12 on the stack
|
|
sa # remove it from the stack (s), and put it in register 'a'
|
|
10 # put 10 on the stack
|
|
la # read (l) the value of register 'a' and push it on the stack
|
|
+p # add the 2 values and print
|
|
EOF
|
|
</code>
|
|
|
|
The above snippet uses newlines to embed comments, but it doesn't
|
|
really matter, you can use ''echo '12sa10la+p'| dc'', with the same results.
|
|
|
|
The register can contain more than just a value, **each register is a
|
|
stack on its own**.
|
|
|
|
<code>
|
|
dc <<EOF
|
|
12sa #store 12 in 'a'
|
|
6Sa # with a capital S the 6 is removed
|
|
# from the main stack and pushed on the 'a' stack
|
|
lap # prints 6, the value at the top of the 'a' stack
|
|
lap # still prints 6
|
|
Lap # prints 6 also but with a capital L, it pushes the value in 'a'
|
|
# to the main stack and pulls it from the 'a' stack
|
|
lap # prints 12, which is now at the top of the stack
|
|
EOF
|
|
</code>
|
|
|
|
===== Macros =====
|
|
|
|
''dc'' lets you push arbitrary strings on the stack when the strings are enclosed in ''[]''.
|
|
You can print it with ''p'': ''<nowiki>dc <<< '[Hello World!]p'</nowiki>'' and you can
|
|
evalute it with x: ''<nowiki>dc <<< '[1 2+]xp'</nowiki>''.
|
|
|
|
This is not that interesting until combined with registers.
|
|
First, let's say we want to calculate the square of a number
|
|
(don't forget to include ''f'' if you get lost!):
|
|
<code>
|
|
dc << EOF
|
|
3 # push our number on the stack
|
|
d # duplicate it i.e. push 3 on the stack again
|
|
d**p # duplicate again and calculate the product and print
|
|
EOF
|
|
</code>
|
|
|
|
Now we have several cubes to calculate, we could use ''<nowiki>dd**</nowiki>'' several times, or
|
|
use a macro.
|
|
|
|
<code>
|
|
dc << EOF
|
|
[dd**] # push a string
|
|
sa # save it in register a
|
|
3 # push 3 on the stack
|
|
lax # push the string "dd**" on the stack and execute it
|
|
p # print the result
|
|
4laxp # same operation for 4, in one line
|
|
EOF
|
|
</code>
|
|
|
|
===== Conditionals and Loops =====
|
|
|
|
''dc'' can execute a macro stored in a register using the ''lR x'' combo, but
|
|
it can also execute macros conditionally. ''>a'' will execute the macro
|
|
stored in the register ''a'', if the top of the stack is //greater than// the second
|
|
element of the stack. Note: the top of the stack contains the last entry.
|
|
When written, it appears as the reverse of what we are used to reading:
|
|
|
|
<code>
|
|
dc << EOF
|
|
[[Hello World]p] sR # store in 'R' a macro that prints Hello World
|
|
2 1 >R # do nothing 1 is at the top 2 is the second element
|
|
1 2 >R # prints Hello World
|
|
EOF
|
|
</code>
|
|
|
|
Some ''dc'' have ''>R <R =R'', GNU ''dc'' had some more, check your manual. Note
|
|
that the test "consumes" its operands: the 2 first elements are popped
|
|
off the stack (you can verify that ''<nowiki>dc <<< "[f]sR 2 1 >R 1 2 >R f"</nowiki>''
|
|
doesn't print anything)
|
|
|
|
Have you noticed how we can //include// a macro (string) in a macro? and as ''dc''
|
|
relies on a stack we can, in fact, use the macro recursively (have your
|
|
favorite control-c key combo ready ;)) :
|
|
|
|
<code>
|
|
dc << EOF
|
|
[ [Hello World] p # our macro starts by printing Hello World
|
|
lRx ] # and then executes the macro in R
|
|
sR # we store it in the register R
|
|
lRx # and finally executes it.
|
|
EOF
|
|
</code>
|
|
|
|
We have recursivity, we have test, we have loops:
|
|
|
|
<code>
|
|
dc << EOF
|
|
[ li # put our index i on the stack
|
|
p # print it, to see what's going on
|
|
1 - # we decrement the index by one
|
|
si # store decremented index (i=i-1)
|
|
0 li >L # if i > 0 then execute L
|
|
] sL # store our macro with the name L
|
|
|
|
10 si # let's give to our index the value 10
|
|
lLx # and start our loop
|
|
EOF
|
|
</code>
|
|
|
|
Of course code written this way is far too easy to read! Make sure to
|
|
remove all those extra spaces newlines and comments:
|
|
|
|
<code>
|
|
dc <<< '[lip1-si0li>L]sL10silLx'
|
|
dc <<< '[p1-d0<L]sL10lLx' # use the stack instead of a register
|
|
</code>
|
|
|
|
I'll let you figure out the second example, it's not hard, it uses the stack
|
|
instead of a register for the index.
|
|
|
|
===== Next =====
|
|
|
|
Check your dc manual, i haven't decribed everything, like arrays
|
|
(only documented with "; : are used by bc(1) for array operations" on solaris,
|
|
probably because //echo '1 0:a 0Sa 2 0:a La 0;ap' | dc// results in
|
|
//Segmentation Fault (core dump) //, the latest solaris uses GNU dc)
|
|
|
|
You can find more info and dc programs here:
|
|
* [[http://en.wikipedia.org/wiki/Dc_(Unix)|http://en.wikipedia.org/wiki/Dc_(Unix)]]
|
|
|
|
And more example, as well as a dc implementation in python here:
|
|
* http://en.literateprograms.org/Category:Programming_language:dc
|
|
* http://en.literateprograms.org/Desk_calculator_%28Python%29
|
|
|
|
The manual for the 1971 dc from Bell Labs:
|
|
* http://cm.bell-labs.com/cm/cs/who/dmr/man12.ps (dead link)</textarea>
|
|
<div id="wiki__editbar" class="editBar">
|
|
<div id="size__ctl">
|
|
</div>
|
|
</div>
|
|
</div></form>
|
|
</div>
|
|
</div><!-- /content --></div>
|
|
</div>
|
|
</div>
|
|
|
|
<div class="small text-right">
|
|
|
|
<span class="docInfo">
|
|
<ul class="list-inline"><li><span class="iconify text-muted" data-icon="mdi:file-document-outline"></span> <span title="howto/calculate-dc.txt">howto/calculate-dc.txt</span></li><li><span class="iconify text-muted" data-icon="mdi:calendar"></span> Last modified: <span title="2018/06/21 23:36">2018/06/21 23:36</span></li><li class="text-muted">by <bdi>izxle</bdi></li></ul> </span>
|
|
|
|
|
|
</div>
|
|
|
|
</article>
|
|
|
|
|
|
</div>
|
|
|
|
</main>
|
|
|
|
<footer id="dw__footer" class="dw-container py-5 dokuwiki container-fluid">
|
|
<hr/>
|
|
<div align="center">
|
|
<h3><a target="_blank" href="http://web.archive.org/web/20220615023700/http://www.performing-databases.com/">This site is supported by Performing Databases - your experts for database administration</a></h3>
|
|
</div>
|
|
<hr/>
|
|
<div align="center">
|
|
<script async src="//web.archive.org/web/20220615023700js_/https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
|
|
<!-- BHORG_BOTTOM -->
|
|
<ins class="adsbygoogle" style="display:inline-block;width:728px;height:90px" data-ad-client="ca-pub-4658830517838678" data-ad-slot="1603598940"></ins>
|
|
<script>
|
|
(adsbygoogle = window.adsbygoogle || []).push({});
|
|
</script>
|
|
</div>
|
|
|
|
<!-- footer -->
|
|
<div class="dw-container small container-fluid mx-5">
|
|
|
|
|
|
<div class="footer-dw-title">
|
|
<div class="media">
|
|
<div class="media-left">
|
|
<img src="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/images/logo.png" alt="Bash Hackers Wiki" class="media-object" style="height:32px"/>
|
|
</div>
|
|
<div class="media-body">
|
|
<div class="row">
|
|
<div class="col-sm-2">
|
|
<h4 class="media-heading">Bash Hackers Wiki</h4>
|
|
<p>
|
|
</p>
|
|
</div>
|
|
<div class="col-sm-10">
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
|
|
<div class="footer-license row">
|
|
<hr/>
|
|
<div id="dw__license" class="col-sm-6">
|
|
<p>
|
|
<a href="http://web.archive.org/web/20220615023700/http://www.gnu.org/licenses/fdl-1.3.html" title="GNU Free Documentation License 1.3" target="" itemscope itemtype="http://schema.org/CreativeWork" itemprop="license" rel="license" class="license"><img src="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/tpl/bootstrap3/images/license/gnufdl.png" width="24" height="24" alt="gnufdl"/> </a> </p>
|
|
<p class="small">
|
|
Except where otherwise noted, content on this wiki is licensed under the following license:<br/><a href="http://web.archive.org/web/20220615023700/http://www.gnu.org/licenses/fdl-1.3.html" title="GNU Free Documentation License 1.3" target="" itemscope itemtype="http://schema.org/CreativeWork" itemprop="license" rel="license" class="license">GNU Free Documentation License 1.3</a> </p>
|
|
</div>
|
|
|
|
<div class="col-sm-6">
|
|
</div>
|
|
|
|
</div>
|
|
|
|
</div>
|
|
<!-- /footer -->
|
|
</footer>
|
|
|
|
<a href="#dokuwiki__top" class="back-to-top hidden-print btn btn-default" title="skip to content" accesskey="t">
|
|
<span class="iconify" data-icon="mdi:chevron-up"></span> </a>
|
|
|
|
<div id="screen__mode"> <span class="visible-xs-block"></span>
|
|
<span class="visible-sm-block"></span>
|
|
<span class="visible-md-block"></span>
|
|
<span class="visible-lg-block"></span>
|
|
</div>
|
|
|
|
<img src="/web/20220615023700im_/https://wiki.bash-hackers.org/lib/exe/indexer.php?id=howto%3Acalculate-dc&1655260622" width="2" height="1" alt=""/>
|
|
</div>
|
|
|
|
</body>
|
|
</html>
|
|
<!--
|
|
FILE ARCHIVED ON 02:37:00 Jun 15, 2022 AND RETRIEVED FROM THE
|
|
INTERNET ARCHIVE ON 11:35:52 Apr 14, 2023.
|
|
JAVASCRIPT APPENDED BY WAYBACK MACHINE, COPYRIGHT INTERNET ARCHIVE.
|
|
|
|
ALL OTHER CONTENT MAY ALSO BE PROTECTED BY COPYRIGHT (17 U.S.C.
|
|
SECTION 108(a)(3)).
|
|
-->
|
|
<!--
|
|
playback timings (ms):
|
|
captures_list: 103.845
|
|
exclusion.robots: 0.22
|
|
exclusion.robots.policy: 0.185
|
|
cdx.remote: 0.09
|
|
esindex: 0.013
|
|
LoadShardBlock: 75.779 (3)
|
|
PetaboxLoader3.datanode: 76.279 (4)
|
|
load_resource: 442.589
|
|
PetaboxLoader3.resolve: 398.827
|
|
--> |