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which (command)
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<h2 id="implementations">Implementations</h2> <h3>Unix, Unix-like, Multics</h3> <p>The command takes one or more arguments; for each of these arguments, it prints the full path of the executable to <a href="/facts/Stdout/r92M7Wd4">stdout</a> that would have been executed if this argument had been entered into the <a href="/facts/Unix_shell/2G4T2Fb9">shell</a>. It does this by searching for an executable or script in the directories listed in the environment variable <a href="/facts/PATH_(variable)/9Xu9Ifrv">PATH</a>. The <i>which</i> command is part of most <a href="/facts/Unix-like/YAKrAxzd">Unix-like</a> computers. It is also part of the <a href="/facts/C_Shell/8XRuIg0K">C Shell</a>.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> </p><p>A which command first appeared in <a href="/facts/3BSD/VUMqqYzx">3BSD</a>.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> </p><p>Carlo Wood developed the <a href="/facts/GNU/HlAKKBdt">GNU</a> implementation used in most <a href="/facts/Linux/9FvCKSTq">Linux</a>-based operating systems.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p><p>On FreeBSD, the which utility was originally written in <a href="/facts/Perl/fx31kjlT">Perl</a> by Wolfram Schneider. The current version of which was rewritten by Daniel Papasian using the <a href="/facts/C_(programming_language)/Ky2No763">C</a> <a href="/facts/Programming_language/cWTYbgWa">programming language</a>.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p><p><a href="/facts/Multics/y7A5peyu">Multics</a> uses the command where abbreviated as wh. </p> <h3>Microsoft Windows, MS-DOS, FreeDOS</h3> <p>The command is available as a separate package for <a href="/facts/Microsoft_Windows/bwhAhuSL">Microsoft Windows</a> as part of the <a href="/facts/GnuWin32/tHohzouq">GnuWin32</a> project<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> and the <a href="/facts/UnxUtils/CsUBGmUM">UnxUtils</a> collection of <a href="/facts/Native_(computing)/yNez4jAK">native</a> <a href="/facts/Windows_API/RRw4RtTu">Win32</a> <a href="/facts/Porting/7s6tFs8B">ports</a> of common <a href="/facts/GNU/HlAKKBdt">GNU</a> <a href="/facts/Unix-like/YAKrAxzd">Unix-like</a> <a href="/facts/Utility/wlMDG74L">utilities</a>.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> Windows also includes the similar where.exe command. </p><p>The same functionality is available in <a href="/facts/MS-DOS/fVrrz1uN">MS-DOS</a>, but not Windows, as the built-in <a href="/facts/TRUENAME/d72UqhJ3">TRUENAME</a> command. </p><p>In <a href="/facts/PowerShell/G1d10lwn">PowerShell</a>, the functionality is provided by the Get-Command Cmdlet.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p><p>The <a href="/facts/FreeDOS/61fuGd0j">FreeDOS</a> version was developed by Trane Francks.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> </p> <h3>AmigaOS compatible</h3> <p>The command is used to find and print the location of a specific program.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p><p>Inputs: </p> <ul><li>FILE – Specifies the command to search for</li> <li>NORES – Resident programs are not included in the search</li> <li>RES – Only resident programs are considered</li> <li>ALL – Will find all locations of the FILE, which may cause the printing of the same location several times</li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="https://www.freebsd.org/cgi/man.cgi?query=which&sektion=1">which(1)</a> – <a href="/facts/FreeBSD/RKsFTm7F">FreeBSD</a> General Commands <a href="/facts/Man_page/S2yYjy0J">Manual</a></li> <li><a href="https://man.openbsd.org/which.1">which(1)</a> – <a href="/facts/OpenBSD/xmPS9tek">OpenBSD</a> General Commands <a href="/facts/Man_page/S2yYjy0J">Manual</a></li> <li><a href="https://docs.oracle.com/cd/E88353_01/html/E37839/which-1.html">which(1)</a> – <a href="/facts/Solaris_(operating_system)/KPfT98EJ">Solaris 11.4</a> User Commands Reference <a href="/facts/Man_page/S2yYjy0J">Manual</a></li> <li><a href="https://linux.die.net/man/1/which">which(1)</a> – <a href="/facts/Linux/9FvCKSTq">Linux</a> User Commands <a href="/facts/Man_page/S2yYjy0J">Manual</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"AROS Research Operating System". <a href="http://aros.sourceforge.net/documentation/users/shell/index.php" target="_blank">http://aros.sourceforge.net/documentation/users/shell/index.php</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"FreeDOS 1.2 Updates Group - Utilities". Ibiblio.org. Retrieved 2022-09-08. <a href="http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html" target="_blank">http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>which for Windows from the GnuWin32 project <a href="http://gnuwin32.sourceforge.net/packages/which.htm" target="_blank">http://gnuwin32.sourceforge.net/packages/which.htm</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>"Command", The Open group base specification, Issue 7, IEEE std 1003.1-2008 <a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html" target="_blank">http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"Command", The Open group base specification, Issue 7, IEEE std 1003.1-2008 <a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html" target="_blank">http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>which(1) – OpenBSD General Commands Manual <a href="https://man.openbsd.org/which.1" target="_blank">https://man.openbsd.org/which.1</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>which(1) – Linux User Commands Manual <a href="https://linux.die.net/man/1/which" target="_blank">https://linux.die.net/man/1/which</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>which(1) – FreeBSD General Commands Manual <a href="https://www.freebsd.org/cgi/man.cgi?query=which&sektion=1" target="_blank">https://www.freebsd.org/cgi/man.cgi?query=which&sektion=1</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>which for Windows from the GnuWin32 project <a href="http://gnuwin32.sourceforge.net/packages/which.htm" target="_blank">http://gnuwin32.sourceforge.net/packages/which.htm</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>"Native Win32 ports of some GNU utilities". Unxutils.sourceforge.net. Retrieved 2022-09-08. <a href="http://unxutils.sourceforge.net/" target="_blank">http://unxutils.sourceforge.net/</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>"Get-Command (Microsoft.PowerShell.Core) - PowerShell". <a href="https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/get-command?view=powershell-3.0" target="_blank">https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/get-command?view=powershell-3.0</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>"FreeDOS 1.2 Updates Package - which (Unix-like)". Ibiblio.org. 2002-03-20. Retrieved 2022-09-08. <a href="http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/which.html" target="_blank">http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/which.html</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>"AROS Research Operating System". <a href="http://aros.sourceforge.net/documentation/users/shell/which.php" target="_blank">http://aros.sourceforge.net/documentation/users/shell/which.php</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> </ol>