Master the Linux whereis Command for Lightning‑Fast File Location

Command Syntax

whereis [options] filename

Purpose

whereis locates the executable, source code, and manual (help) files of a given program name. It can also search for unusual items and specify alternative search paths.

How It Works

Unlike find, whereis reads from a pre‑built database that records the locations of all files, making searches extremely fast. The database is refreshed only about once a week, so recent changes may not be reflected.

Options

-b  Locate binary (executable) files.

-m  Locate manual/help files.

-s  Locate source code files.

-u  Search for files outside the default binary, source, and help categories.

-B  Specify a custom search path for binaries.

-M  Specify a custom search path for manual files.

-S  Specify a custom search path for source files.

Examples

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

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

whereis -m ls

Note: The last command returns no output if the manual page is not found in the database.