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<!doctype html><html lang=en class=no-js> <head><meta charset=utf-8><meta name=viewport content="width=device-width,initial-scale=1"><link href=https://flokoe.github.io/bash-hackers-wiki/commands/builtin/set/ rel=canonical><link href=../return/ rel=prev><link href=../shift/ rel=next><link rel=icon href=../../../assets/images/favicon.png><meta name=generator content="mkdocs-1.6.1, mkdocs-material-9.5.44"><title>The set builtin command - The Bash Hackers Wiki</title><link rel=stylesheet href=../../../assets/stylesheets/main.0253249f.min.css><link rel=stylesheet href=../../../assets/stylesheets/palette.06af60db.min.css><link rel=preconnect href=https://fonts.gstatic.com crossorigin><link rel=stylesheet href="https://fonts.googleapis.com/css?family=Roboto:300,300i,400,400i,700,700i%7CRoboto+Mono:400,400i,700,700i&display=fallback"><style>:root{--md-text-font:"Roboto";--md-code-font:"Roboto Mono"}</style><script>__md_scope=new URL("../../..",location),__md_hash=e=>[...e].reduce(((e,_)=>(e<<5)-e+_.charCodeAt(0)),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script></head> <body dir=ltr data-md-color-scheme=default data-md-color-primary=indigo data-md-color-accent=indigo> <input class=md-toggle data-md-toggle=drawer type=checkbox id=__drawer autocomplete=off> <input class=md-toggle data-md-toggle=search type=checkbox id=__search autocomplete=off> <label class=md-overlay for=__drawer></label> <div data-md-component=skip> <a href=#the-set-builtin-command class=md-skip> Skip to content </a> </div> <div data-md-component=announce> </div> <header class=md-header data-md-component=header> <nav class="md-header__inner md-grid" aria-label=Header> <a href=../../.. title="The Bash Hackers Wiki" class="md-header__button md-logo" aria-label="The Bash Hackers Wiki" data-md-component=logo> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M12 8a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3 3 3 0 0 0 3 3m0 3.54C9.64 9.35 6.5 8 3 8v11c3.5 0 6.64 1.35 9 3.54 2.36-2.19 5.5-3.54 9-3.54V8c-3.5 0-6.64 1.35-9 3.54"/></svg> </a> <label class="md-header__button md-icon" for=__drawer> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M3 6h18v2H3zm0 5h18v2H3zm0 5h18v2H3z"/></svg> </label> <div class=md-header__title data-md-component=header-title> <div class=md-header__ellipsis> <div class=md-header__topic> <span class=md-ellipsis> The Bash Hackers Wiki </span> </div> <div class=md-header__topic data-md-component=header-topic> <span class=md-ellipsis> The set builtin command </span> </div> </div> </div> <form class=md-header__option data-md-component=palette> <input class=md-option data-md-color-media data-md-color-scheme=default data-md-color-primary=indigo data-md-color-accent=indigo aria-label="Switch to dark mode" type=radio name=__palette id=__palette_0> <label class="md-header__button md-icon" title="Switch to dark mode" for=__palette_1 hidden> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M12 8a4 4 0 0 0-4 4 4 4 0 0 0 4 4 4 4 0 0 0 4-4 4 4 0 0 0-4-4m0 10a6 6 0 0 1-6-6 6 6 0 0 1 6-6 6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg> </label> <input class=md-option data-md-color-media data-md-color-scheme=slate data-md-color-primary=indigo data-md-color-accent=indigo aria-label="Switch to light mode" type=radio name=__palette id=__palette_1> <label class="md-header__button md-icon" title="Switch to light mode" for=__palette_0 hidden> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M12 18c-.89 0-1.74-.2-2.5-.55C11.56 16.5 13 14.42 13 12s-1.44-4.5-3.5-5.45C10.26 6.2 11.11 6 12 6a6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg> </label> </form> <script>var palette=__md_get("__palette");if(palette&&palette.color){if("(prefers-color-scheme)"===palette.color.media){var media=ma
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</code></pre></div> <h2 id=description>Description<a class=headerlink href=#description title="Permanent link">¶</a></h2> <p><code>set</code> is primarily made to</p> <ul> <li>set the positional parameters (see <a href=../../../scripting/posparams/ >handling positional parameters</a>) to <code><POSPARAMS></code></li> <li>set shell attributes with short options (see below)</li> <li>set shell attributes with long option names (see below)</li> </ul> <p>Without any options, <code>set</code> displays all shell- and environment-variables (only is POSIX-mode) in a re-usable format <code>NAME=VALUE</code>.</p> <h3 id=attributes>Attributes<a class=headerlink href=#attributes title="Permanent link">¶</a></h3> <p>All attributes below can be switched on using <code>-X</code> and switched off using <code>+X</code>. This is done because of the historical meaning of the <code>-</code> to set flags (true for most commands on UNIX®).</p> <table> <thead> <tr> <th>Flag</th> <th>Optionname</th> <th>Description</th> </tr> </thead> <tbody> <tr> <td><code>-a</code></td> <td><code>allexport</code></td> <td>Automatically mark new and altered variables to be exported to subsequent environments.</td> </tr> <tr> <td><code>-b</code></td> <td><code>notify</code></td> <td>Don't wait for the next prompt to print when showing the reports for a terminated background job (only with job control)</td> </tr> <tr> <td><code>-e</code></td> <td><code>errexit</code></td> <td>When set, the shell exits when a simple command in a command list exits non-zero (<code>FALSE</code>). This is not done in situations, where the exit code is already checked (<code>if</code>, <code>while</code>, <code>until</code>, <code>||</code>, <code>&&</code>)</td> </tr> <tr> <td><code>-f</code></td> <td><code>noglob</code></td> <td>Disable <a href=../../../syntax/expansion/globs/ >pathname expansion</a> (globbing)</td> </tr> <tr> <td><code>-h</code></td> <td><code>hashall</code></td> <td>Remembers the location of commands when they're called (hashing). Enabled by default.</td> </tr> <tr> <td><code>-k</code></td> <td><code>keyword</code></td> <td>Allows to place environment-assignments everywhere in the commandline, not only infront of the called command.</td> </tr> <tr> <td><code>-m</code></td> <td><code>monitor</code></td> <td><strong>Monitor mode</strong>. With job control, a short descriptive line is printed when a backgroud job ends. Default is "on" for interactive shells (with job control).</td> </tr> <tr> <td><code>-n</code></td> <td><code>noexec</code></td> <td>Read and parse but <strong>do not execute commands</strong> - useful for checking scripts for syntax errors. Ignored by interactive shells.</td> </tr> <tr> <td><code>-o</code></td> <td></td> <td>Set/unset attributes with long option names, e.g. <code>set -o noglob</code>. The long option names are in the second column of this table. If no option name is given, all options are printed with their current status.</td> </tr> <tr> <td><code>-p</code></td> <td><code>privileged</code></td> <td>Turn on privileged mode.</td> </tr> <tr> <td><code>-t</code></td> <td><code>onecmd</code></td> <td>Exit after reading and executing <strong>one</strong> command.</td> </tr> <tr> <td><code>-u</code></td> <td><code>nounset</code></td> <td>Treat unset variables as an error when performing parameter expansion. Non-interactive shells exit on this error.</td> </tr> <tr> <td><code>-v</code></td> <td><code>verbose</code></td> <td>Print shell input lines as they are read - useful for debugging.</td> </tr> <tr> <td><code>-x</code></td> <td><code>xtrace</code></td> <td>Print commands just before execution - with all expansions and substitutions done, and words marked - useful for debugging.</td> </tr> <tr> <td><code>-B</code></td> <td><code>braceexpand</code></td> <td>The shell performs <a href=../../../syntax/expansion/brace/ >brace expansion</a> This is on by default.</td> </tr> <tr> <td><code>-C</code></td> <td><code>noclobber</code></td> <td>Don't overwrite files on redirection operations. You can override that by spe
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<a id=__codelineno-0-3 name=__codelineno-0-3 href=#__codelineno-0-3></a><span class=nb>set</span><span class=w> </span>-x<span class=w> </span><span class=c1># on</span>
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<a id=__codelineno-0-5 name=__codelineno-0-5 href=#__codelineno-0-5></a><span class=nb>set</span><span class=w> </span>+x<span class=w> </span><span class=c1># off</span>
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</code></pre></div> <h2 id=portability-considerations>Portability considerations<a class=headerlink href=#portability-considerations title="Permanent link">¶</a></h2> <p><code>set</code> and its basic behaviour and options are specified by POSIX®. However, options that influence Bash-specific things are not portable, naturally.</p> <h2 id=see-also>See also<a class=headerlink href=#see-also title="Permanent link">¶</a></h2> <ul> <li>Internal: <a href=../shopt/ >The shopt builtin command</a></li> </ul> <aside class=md-source-file> <span class=md-source-file__fact> <span class=md-icon title="Last update"> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M21 13.1c-.1 0-.3.1-.4.2l-1 1 2.1 2.1 1-1c.2-.2.2-.6 0-.8l-1.3-1.3c-.1-.1-.2-.2-.4-.2m-1.9 1.8-6.1 6V23h2.1l6.1-6.1zM12.5 7v5.2l4 2.4-1 1L11 13V7zM11 21.9c-5.1-.5-9-4.8-9-9.9C2 6.5 6.5 2 12 2c5.3 0 9.6 4.1 10 9.3-.3-.1-.6-.2-1-.2s-.7.1-1 .2C19.6 7.2 16.2 4 12 4c-4.4 0-8 3.6-8 8 0 4.1 3.1 7.5 7.1 7.9l-.1.2z"/></svg> </span> <span class="git-revision-date-localized-plugin git-revision-date-localized-plugin-date">November 13, 2024</span> </span> <span class=md-source-file__fact> <span class=md-icon title=Created> <svg xmlns=http://www.w3.org/2000/svg viewbox="0 0 24 24"><path d="M14.47 15.08 11 13V7h1.5v5.25l3.08 1.83c-.41.28-.79.62-1.11 1m-1.39 4.84c-.36.05-.71.08-1.08.08-4.42 0-8-3.58-8-8s3.58-8 8-8 8 3.58 8 8c0 .37-.03.72-.08 1.08.69.1 1.33.32 1.92.64.1-.56.16-1.13.16-1.72 0-5.5-4.5-10-10-10S2 6.5 2 12s4.47 10 10 10c.59 0 1.16-.06 1.72-.16-.32-.59-.54-1.23-.64-1.92M18 15v3h-3v2h3v3h2v-3h3v-2h-3v-3z"/></svg> </span> <span class="git-revision-date-localized-plugin git-revision-date-localized-plugin-date">November 13, 2024</span> </span> </aside> <h2 id=__comments>Comments</h2> <script src=https://giscus.app/client.js data-repo=flokoe/bash-hackers-wiki data-repo-id=R_kgDOJ3Nr6Q data-category="Giscus Page Comments" data-category-id=DIC_kwDOJ3Nr6c4CXq9t data-mapping=pathname data-strict=1 data-reactions-enabled=1 data-emit-metadata=0 data-input-position=top data-theme=preferred_color_scheme data-lang=en data-loading=lazy crossorigin=anonymous async>
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