Commands tagged which

or

For example, I write

in my `~/.bashrc`.

whereis (1) - locate the binary, source, and manual page files for a command

Not actually better, just expanded a bit. The "whereis" command has the following output:

whereis gcc

gcc: /usr/bin/gcc /usr/lib/gcc /usr/bin/X11/gcc /usr/share/man/man1/gcc.1.gz

therefore the 'ls' error on first line, which could be eliminated with a little extra work.

this is the much easier zsh equivalent ...

it is generally advised to avoid using which(1) whenever possible. which(1) is usually a csh(1) script, or sometimes a compiled binary. It's output is highly variable from operating system to operating system, so platform independent scripts could become quite complicated with the logic. On HP-UX 10.20, for example, it prints "no bash in /path /path /path ..."; on OpenBSD 4.1, it prints "bash: Command not found."; on Debian (3.1 through 5.0 at least) and SuSE, it prints nothing at all; on Red Hat 5.2, it prints "which: no bash in (/path:/path:...)"; on Red Hat 6.2, it writes the same message, but on standard error instead of standard output; and on Gentoo, it writes something on stderr. And given all these differences, it's still variable based on your shell. This is why POSIX is king. See http://mywiki.wooledge.org/BashFAQ/081 for more ways on avoiding which(1).

This version builds on my command 8776 (Find the package a command belongs to on debian-based distros). So if you use that command to find package name then you could alternatively use following for

package summary:

Tested with bash v4.1.5 on ubuntu 10.10

Limitations:

as written above, only works for programs with no file extention (i.e 'proggy', but not 'proggy.sh')

because \eb maps to readine function backward-word rather then shell-backward-word (which

is unbinded by default on ubuntu), and correspondingly for \ef.

if you're willing to have Ctrl-f and Ctrl-g taken up too , you can insert the following lines

into ~/.inputrc, in which case invoking Ctrl-e will do the right thing both for "proggy" and "proggy.sh".

-- cut here --

\C-f:shell-backward-word

\C-g:shell-forward-word

"\C-e":"\C-f`which \C-g`\e\C-e"

-- cut here --

5 helpful aliases for using the which utility, specifically for the GNU which (2.16 tested) that is included in coreutils.

Which is run first for a command. Same as type builtin minus verbosity

Which (a)lias

Which (f)unction

Which e(x)ecutable file in PATH

Which (all) alias, function, builtin, and files in PATH

# From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

This will show you any links that a command follows (unlike 'file -L'), as well as the ultimate binary or script.

Put the name of the command at the very end; this will be passed to perl as the first argument.

For obvious reasons, this doesn't work with aliases or functions.

You may also use the $(which foo) variant instead of backticks. I personnaly have an alias ll='ls -l'.

In Debian based distros, this command will list 'binutils' package details which contains 'nm' command. You can replace 'nm' to any other command.

Often I need to edit a bash or perl script I've written. I know it's in my path but I don't feel like typing the whole path (or I don't remember the path).

Replace 'more' command with any command which is in your PATH.