Several Unix dialects use the
whereis command to find where programs, or executables, are stored in the file structure of the computer. To use it at the Unix prompt, enter:
command with the name of the executable for which you are looking. For example, if you are looking for the location of the lpr command, you would enter:
whereis command will return something like the following:
lpr: /usr/ucb/lpr /usr/man/man1/lpr.1
In this example, the query asked about the
lpr command, which spools jobs to printers. The operating system returned two answers, and thus two paths. The first path is the location of the
lpr executable, and the second path is the location of the
lpr manual page.
To find the path the operating system uses to execute a command when you enter it on the command line, use the
which command instead, for example:
This command will output something like the following:
This means that when you enter
lpr at the command line, the system is really executing
Note :- There is also type command which tells about type of any command.