I know that when you are on shell, the only commands that can be used are the ones that can be found on some directory set on PATH. Even I don't know how to see what dirs are on my PATH variable (and this is another good question that could be answered), what I'd like to know is:
I come to shell and write:
$ lshw I want to know a command on shell that can tell me WHERE this command is located. In other words, where this "executable file" is located?
Something like:
$ location lshw /usr/bin 8 Answers
If you're using Bash or zsh, use this:
type -a lshw This will show whether the target is a builtin, a function, an alias or an external executable. If the latter, it will show each place it appears in your PATH.
bash$ type -a lshw lshw is /usr/bin/lshw bash$ type -a ls ls is aliased to `ls --color=auto' ls is /bin/ls bash$ zsh zsh% type -a which which is a shell builtin which is /usr/bin/which In Bash, for functions type -a will also display the function definition. You can use declare -f functionname to do the same thing (you have to use that for zsh, since type -a doesn't).
Like this:
which lshw To see all of the commands that match in your path:
which -a lshw PATH is an environment variable, and can be displayed with the echo command:
echo $PATH It's a list of paths separated by the colon character ':'
The which command tells you which file gets executed when you run a command:
which lshw sometimes what you get is a path to a symlink; if you want to trace that link to where the actual executable lives, you can use readlink and feed it the output of which:
readlink -f $(which lshw) The -f parameter instructs readlink to keep following the symlink recursively.
Here's an example from my machine:
$ which firefox /usr/bin/firefox $ readlink -f $(which firefox) /usr/lib/firefox-3.6.3/firefox.sh ~$ echo $PATH /home/jack/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games ~$ whereis lshw lshw: /usr/bin/lshw /usr/share/man/man1/lshw.1.gz In the TENEX C Shell, tcsh, one can list a command's location(s), or if it is a built-in command, using the where command e.g.:
tcsh% where python /usr/local/bin/python /usr/bin/python tcsh% where cd cd is a shell built-in /usr/bin/cd An alternative to type -a is command -V
Since most of the times I am interested in the first result only, I also pipe from head. This way the screen will not flood with code in case of a bash function.
command -V lshw | head -n1 The Korn shell, ksh, offers the whence built-in, which identifies other shell built-ins, macros, etc. The which command is more portable, however.
TLDR Answer
Use: whereis -b lshw.
Explanation
Use the whereis command. From the man page:
whereis- locate the binary, source, and manual page files for a command
Commonly-Used Switches
In addition, you can specify what you're looking for:
whereis -b packagename: Source for location of binaries.whereis -m packagename: Source for location of manuals.whereis -s packagename: Source for location of source code.
In your case, since you're looking for the binary, you'll want: whereis -b lshw.
There are other switches with this command, check them out at the man page. If there is no file associated with a packagename, you'll see a blank line.
Examples
Here's some real world use:
holdoffhunger@tower:~$ whereis grep grep: /bin/grep /usr/share/man/man1/grep.1.gz /usr/share/man/man1/grep.1posix.gz holdoffhunger@tower:~$ whereis -m grep grep: /usr/share/man/man1/grep.1.gz /usr/share/man/man1/grep.1posix.gz holdoffhunger@tower:~$ whereis -s grep grep: 
