I would like to take the output of a which command, and cd to the parent directory. For example, say I have the following:
which someprogram
With output:
/home/me/somedirectory/someprogram
And I would like to cd to the directory that someprogram lives in:
cd /home/me/somedirectory
I'd like to accomplish this in one line. What is the most elegant, tricky, short way to do this?
Use dirname:
cd "`dirname $(which program)`"
$() instead of backticks: cd $(dirname $(which program))
$() due to the many advantages of $() over backticks.
In bash, I recommend type -p over which. which is an external command and it's tricky at times. You can use sed to remove everything after the final /, or use the special-purpose dirname utility.
cd "$(dirname -- "$(type -p program)")"
cd "$(type -p program | sed 's:[^/]*$::')"
On the command line, if you know that the directory doesn't contain any special characters (whitespace or \[?*), you can omit the quotes. You can also use backquotes instead of one of the $(…) (nesting backquotes is difficult, not worth it here).
cd `dirname $(type -p program)`
cd $(dirname `type -p program`)
cd `type -p program | sed 's:[^/]*$::'`
In zsh, there's a more compact syntax.
cd ${$(whence -p program):h}
cd ${$(echo =program):h}
cd ${${_+=program}:h}
(Yes, that last one is cryptic. It uses the ${VAR+TEXT} syntax on the _ variable, with the value being =program which is equivalent to $(whence -p program).)
