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Determine whether a file exists or not in Bash

Determine whether a file exists or not in Bash

David Y.

—

The Problem

How can I determine whether a file exists in Bash? Conversely, how can I test that it does not exist?

The Solution

We can check whether a file exists using the test command-line utility:

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if test -f /path/to/file; then
  echo "File exists."
fi

To check whether a file does not exist, we can negate the condition with the NOT logical operator, !:

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if ! test -f /path/to/file; then
  echo "File does not exist."
fi

Because the test command is used frequently in Bash expressions, we can write it as [] rather than typing out test:

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if ! [ -f /path/to/file ]; then
  echo "File does not exist."
fi

The -f flag tests whether the provided filename exists and is a regular file. To test for directories instead, we can use the -d flag. To test for both files and directories, we can use the -e flag.

More information about test can be found on its manual page, accessible by typing man test into the terminal.

Further Reading

If you’re looking to get a deeper understanding of how Bash application monitoring works, take a look at the following articles:

  • Syntax.fmListen to the Syntax Podcast
  • ResourcesWhat is Distributed Tracing
  • Syntax.fm logo
    Listen to the Syntax Podcast

    Tasty treats for web developers brought to you by Sentry. Get tips and tricks from Wes Bos and Scott Tolinski.

    SEE EPISODES

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