Master Linux’s whereis Command: Fast File Location Explained

The whereis command can only search for program names and looks for binary files (option -b), manual pages (option -m), and source code files (option -s). If no option is given, it returns all available information.

Compared with find, whereis is much faster because Linux maintains a database of all files; both whereis and the related locate command query this database instead of traversing the disk, resulting in higher efficiency.

The database is not updated in real time; by default it refreshes weekly, so whereis or locate may return paths to files that have been deleted or miss newly created files until the next update.

Command Format

whereis [options]... filename

Command Function

The whereis command locates the executable, source code, and manual (help) files of a program within the file system. It can also search for source code, specify alternative search paths, and find unusual items.

Command Options

-b  Locate binary (executable) files.

-m  Locate manual (help) files.

-s  Locate source code files.

-u  Search for files other than binaries, sources, or manuals in the default paths.

-B  Specify the search path for binaries.

-M  Specify the search path for manual files.

-S  Specify the search path for source files.

Find the location of the ls command and its manual

whereis ls
ls: /usr/bin/ls /usr/share/man/man1/ls.1.gz

Show the binary of ls

whereis -b ls
ls: /usr/bin/ls

Show the manual of ls

whereis -m ls