Check if file is empty in bash

This tutorial illustrates checking if a variable is empty in bash using the test command with the -z and -n options. We use the test command with the -z option. The -z option checks if the length of the string variable is 0. If the length of the string variable is 0 , the test returns true , and the script prints to the standard output that the string variable is empty.

And if the length of the string variable is not 0 , the script prints that the string variable is not empty. Hi Masters I have problem!!! I need to check number of records in a file and if it is zero or file is empty i need to do some task. How to check for empty file in Perl? Hi, May I know how to check for empty file in Perl. Iam missing something, somewhere.

RedHat Commands. OpenSolaris Commands. Linux Commands. SunOS Commands. FreeBSD Commands. Full Man Repository. Advanced Search. Contact Us. Forum Rules. Mark Forums Read. Thread Tools. View Public Profile for stolz. Find all posts by stolz. View Public Profile for vino. In this tutorial I shared brief examples of test operators to check for files and directories.

You can use any attribute from the table I have shared to enhance your script execution with proper tests. Lastly I hope the steps from the article to check if file exists or not on Linux was helpful. So, let me know your suggestions and feedback using the comment section. If my articles on GoLinuxCloud has helped you, kindly consider buying me a coffee as a token of appreciation. For any other feedbacks or questions you can either use the comments section or contact me form.

Most of this stuff has been really helpful. But there is no difference in single and double square brackets on the -f example. I always prefer to use double brackets as a general practice as it avoid unexpected surprises at times. You can read more about them at Is double square brackets [[ ]] preferable over single square brackets [ ] in Bash?

Thanks Kusalananda, I've added this answer, as people might find it useful when using square brackets around the grep condition. The [[ are not part of the if syntax, they are a command that returns status according to some condition. You are already checking status, so you should have just if grep -q … — Jan Hudec.

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