Locating Commands and Files with Whereis Command

Have you ever struggled to find where a command or a file is located on your Linux system? Don't worry! The whereis command can help. In this tutorial, we'll walk you through how to use this command to find file paths in Linux, discover command locations, and explore various options to make the most of this tool.

Understanding whereis

The whereis command is a simple tool for finding the binary, source, and man page files for commands. Whether you're a beginner exploring Linux or an experienced sysadmin, using whereis can make managing your Linux system easier. This tutorial will provide step-by-step examples and tips to help you make the most of this command and enhance your workflow.

Why Use whereis?

The whereis command solves practical problems, such as:

• Locating Binaries: Quickly find where executable commands are stored.
• Finding Source Files: Trace a command back to its source files for development purposes.
• Accessing Man Pages: Easily locate the path to manual pages to learn more about commands.

These functions make whereis an essential part of your Linux toolkit, especially when troubleshooting or managing system configurations.

How to Use whereis Command

Using the whereis command is straightforward. Here is a basic template:

whereis [options] filename

Example 1: Finding the ls Command

Let's locate the popular ls command:

whereis ls

Output:

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

This tells us that the ls command's executable file is located in /bin, and its manual page is in /usr/share/man/man1.

Example 2: Searching for a Source File

If you're interested in source files, the whereis command can sometimes identify them. However, not all binaries will have associated source files on your system.

whereis find

Output (hypothetical):

find: /usr/bin/find /usr/share/man/man1/find.1.gz /usr/src/find

Example 3: Discovering Man Pages

Discover where the man pages for a command reside:

whereis cp

Output:

cp: /bin/cp /usr/share/man/man1/cp.1.gz

Options to Maximize Results

The whereis command features several options that let you tailor your search:

• -b: Locate binaries only.
• -m: Locate man pages only.
• -s: Locate sources only.

Example 4: Locating Binaries Only

If you are only interested in the executable files, you can use -b:

whereis -b mkdir

Output:

mkdir: /bin/mkdir

Example 5: Finding Only Man Pages

In cases where you only need the manual pages:

whereis -m tar

Output:

tar: /usr/share/man/man1/tar.1.gz

Example 6: Using whereis with Multiple Files

You can provide multiple filenames in a single command:

whereis ls cp

Output:

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

Customizing Your Searches

Using Custom Paths

The whereis command allows you to search in custom directories, useful if your files are installed in non-standard locations.

Example 7: Searching with Custom Path for Manuals

Suppose your application documentation is stored in a custom directory. You can search for it using the -M option:

whereis -M /opt/man customapp

This instructs whereis to look in the /opt/man directory for manual pages associated with customapp.

Troubleshooting and Tips

• Command Not Found: If whereis returns nothing, the file might not exist in the default search paths or isn't installed.
• Exhaustive Search: While whereis is powerful, it is not exhaustive. Consider using find or locate for a deeper search.
• Combine Options: Use multiple options to narrow your search, enhancing precision.

Conclusion

The whereis command is a simple yet effective tool for locating binaries, source files, and manual pages in Linux. By mastering its options, you can streamline your search process and focus on more crucial tasks. We hope this guide empowers you to use whereis efficiently and with confidence. Continue exploring the command line, and enjoy the power of Linux at your fingertips!

Happy exploring!