Why Doesn’t find Return Expected Results? Here’s How to Fix It

If you’ve ever run the find command in your Unix-based system, you might have encountered a frustrating situation where the command fails to locate files you know are present. For instance, you may want to search for shell script files, and despite being certain that they exist, the output is empty. This common issue often arises from misunderstandings about how the find command interprets wildcard characters. Let’s delve into the problem and discover the solutions that can get your search back on track.

The Problem: find Not Working as Expected

Consider this command you may have tried:

$ find /usr -name *.sh

This command is intended to search for all files with the .sh extension in the /usr directory. However, if you find that no results appear, you might wonder, Why isn’t find working?

You know the scripts are there; for example, when you run:

$ ls /usr/local/lib/*.sh

You can see files like tclConfig.sh and tkConfig.sh. So then, what is going wrong with your find command?

Understanding the Issue

The main issue at hand is how the command shell interprets the wildcard *.sh. Specifically, if there are any files in your current directory that match *.sh, the shell expands that wildcard before find even gets a chance to act. This can lead to unexpected behavior:

1. Wildcard Expansion

   • If .sh files exist in your current directory, for example, tkConfig.sh, typing find /usr -name *.sh will expand it to find /usr -name tkConfig.sh, effectively limiting your search to just that file.

2. Syntax Errors

   • If multiple files match, find may throw a syntax error due to ambiguous arguments:

     find: bad option tkConfig.sh
     

Solution 1: Quoting the Wildcard

To prevent the shell from expanding the wildcard before passing it to find, you can quote the wildcard character:

• Either use double quotes:

  $ find /usr -name "*.sh"
  

• Or use single quotes:

  $ find /usr -name '*.sh'
  

By quoting *.sh, you’re instructing the shell to pass it as-is to find, thereby enabling it to look for all .sh files in the specified directory.

Solution 2: Following Symlinks

Another potential reason why find might not work as expected is the presence of symbolic links in the /usr directory or its subdirectories. By default, find does not follow symbolic links. If you suspect this to be the case, you can use the -follow option:

$ find /usr -follow -name '*.sh'

This command allows find to traverse symbolic links and search for the desired files.

Conclusion

In summary, if you find that the find command is not producing the expected results when searching for shell scripts, it’s likely due to wildcard expansion or the presence of symbolic links. Always remember to quote your wildcards to prevent premature expansion and, if necessary, use the -follow option. By employing these strategies, you can successfully locate your shell scripts and enhance your command-line proficiency!

Happy Searching!

Now you’re ready to tackle the find command with confidence! If you have any questions or further issues, feel free to leave them in the comments below.