whereis

Locate the binary, source, and manual page files for specified commands/files.

The supplied filenames are first stripped of leading pathname components and any (single) trailing extension of the form .ext (for example, .c). Prefixes of s. resulting from use of source code control are also dealt with. whereis then attempts to locate the desired program in a list of standard Linux directories (e.g., /bin, /etc, /usr/bin, /usr/local/bin/, etc.).

SYNTAX
      whereis [options] files

OPTIONS
   -b    Search only for binaries.

   -B directories
         Change or otherwise limit the directories to search for
         binaries.

   -f    Terminate the last directory list and signal the
         start of filenames;
         Required when any of the -B, -M, or -S options are used.

   -m    Search only for manual sections.

   -M directory
         Change or otherwise limit the directories to search for
         manual sections.

   -s    Search only for sources.

   -S directory
         Change or otherwise limit the directories to search for
         sources.

   -u    Search for unusual entries, that is, files that do not
         have one entry of each requested type.
         Thus, the command whereis -m -u * asks for those files
         in the current directory that have no documentation.

EXAMPLE
Find all files in /usr/bin that are not documented in /usr/man/man1
but that have source in /usr/src:

% cd /usr/bin
% whereis -u -M /usr/man/man1 -S /usr/src -f *

"If I am not for myself, Who will be for me?
And if I am only for myself, What am I?
And if not now, When?" -Hillel

Related commands:

pwd - Print Working Directory
hash - Remember the full pathname of a name argument
which - Show full path of commands