Whereis Command Examples

The whereis command helps users locate the binary, source, and manual page files for a given command. And in this tutorial, I will walk you through practical examples to help you understand how to use whereis command.

Unlike other search commands like find that scan the entire file system, whereis searches predefined directories, making it faster and more efficient.

It is particularly useful for system administrators and developers to locate files related to commands without requiring root privileges.

whereis Command Syntax

To use any command to its maximum potential, it is important to know its syntax and that is why I'm starting this tutorial by introducing the syntax of the whereis command:

whereis [OPTIONS] FILE_NAME...

Here,

• OPTIONS: Flags that modify the search behavior.
• FILE_NAME: The name of the file or command to locate.

Now, let's take a look at available options of the whereis command:

1. Locate all files related to a command

To find all files (binary, source, and manual) related to a command, all you have to do is append the command name to the whereis command as shown here:

whereis command

For example, if I want to locate all files related to bash, then I would use the following:

whereis bash

Here,

• /usr/bin/bash: Path to the binary file.
• /usr/share/man/man1/bash.1.gz: Path to the manual page.

2. Search for binary files only

To locate only the binary (executable) file of a command, use the -b flag along with the target command as shown here:

whereis -b command

If I want to search for the binary files for the ls command, then I would use the following:

whereis -b ls

3. Search for the manual page only

To locate only the manual page for a specific command, use the -m flag along with the targeted command as shown here:

whereis -m command

For example, if I want to search for the manual page location for the grep command, then I would use the following:

whereis -m grep

As you can see, it gave me two locations:

• /usr/share/man/man1/grep.1.gz: A manual page which can be accessed through man grep command.
• /usr/share/info/grep.info.gz: An info page that can be accessed through info grep command.

4. Search for source files only

To find only source code files associated with a command, use the -s flag along with the targeted command as shown here:

whereis -s command

For example, if I want to search source files for the gcc, then I would use the following:

whereis -s gcc

My system is fresh and I haven't installed any packages from the source so I was given a blank output.

5. Specify custom directories for searching

To limit your search to specific directories, use options like -B, -S, or -M. For example, if I want to limit my search to the /bin directory for the cp command, then I would use the following command:

whereis -b -B /bin -f cp

Here,

• -b: This flag tells whereis to search only for binary files (executables), ignoring source and manual files.
• -B /bin: The -B flag specifies a custom directory (/bin in this case) where whereis should look for binary files. It also limits the search to the /bin directory instead of searching all default directories.
• -f cp: Without -f, the whereis command would interpret cp as another directory.

6. Identify commands missing certain files (unusual files)

The whereis command can help you find commands that are missing one or more associated files (binary, source, or manual). This is particularly useful for troubleshooting or verifying file completeness.

For example, to search for commands in the /bin directory that is missing manual pages, you first have to change your directory to /bin and then use the -u flag to search for unusual files:

cd /bin
whereis -u -m *

Wrapping Up...

This was a quick tutorial on how you can use the whereis command in Linux including practical examples and syntax. I hope you will find this guide helpful.

If you have any queries or suggestions, leave us a comment.