Env 1927701 218938134 2008-06-12T21:08:41Z Calvin 1998 5642846 Reverted edits by [[Special:Contributions/24.195.111.186|24.195.111.186]] to last version by DumZiBoT (using [[WP:HG|Huggle]]) {{lowercase|title=env}}{{otheruses}} '''<tt>env</tt>''' is a [[Unix shell|shell]] [[command (computing)|command]] for [[Unix]] and [[Unix-like]] [[operating system]]s. It is used to either print a list of [[environment variable]]s or run another utility in an altered environment without having to modify the currently existing environment. Using <tt>env</tt>, variables may be added or removed, and the values of existing variables may be changed. In practice, <tt>env</tt> has another common use. It is often used by [[shell script]]s to launch the correct [[Interpreter (computing)|interpreter]]. In this usage, the environment is typically not changed. ==Examples== To clear the environment for a new shell: <source lang="bash"> env - /bin/sh </source> To launch the [[X Window]] application [[xcalc]] and have it appear on a different display: <source lang="bash"> env DISPLAY=foo.bar:1.0 xcalc </source> Here is the code of a very simple [[Python (programming language)|Python]] script: <source lang="bash"> #!/usr/bin/env python print "Hello World." </source> In this example, <tt>/usr/bin/env</tt> is the full [[Path (computing)|path]] of the <tt>env</tt> command. The environment is not altered. Note that it is possible to specify the interpreter without using <tt>env</tt>, by giving the full path of the <tt>python</tt> interpreter. A problem with that approach is that on different computer systems, the exact path may be different. By instead using <tt>env</tt> as in the example, the interpreter is searched for and located at the time the script is run. This makes the script more [[Porting|portable]], but also increases the risk that the wrong interpreter is selected because it searches for a match in every directory on the executable search path. ==External links== *[http://www.gnu.org/software/coreutils/manual/html_node/env-invocation.html env] -- manual page from [[GNU]] [[coreutils]]. *{{man|1|env|Linux| run a program in a modified environment}} {{unix commands}} [[Category:Unix software]] [[it:Env (Unix)]] [[ja:Env]] [[pl:Env]] [[ru:Env]]