You simply check if ls with a pattern returns non-zero. Another method is to use the compgen command. You can use the -G option to specify a glob pattern.
Simlar to ls , compgen returns a list of files that are matched. The following shorthand one-liners are also possible. Please note that this article is published by Xmodulo. If you would like to use the whole or any part of this article, you need to cite this web page at Xmodulo. Bash is a shell that interprets commands. You can use a. In this guide, learn how to use a bash command to check if a file or directory exists. Note: You may encounter the term bash script.
This is a sequence of several commands to the shell. A script can be saved as a file and is often used to automate multiple system commands into a single action.
The first line executes the test to see if the file exists. The second command, echo , displays the results 0 meaning that the file exists, 1 means no file was found.
To check if a directory exists, switch out the —f option on the test command for —d for directory :. This command works the same as it does for files, so using brackets instead of the test command works here also. Note: If you are searching for a file or directory because you need to delete it, refer to our guide on removing files and directories with Linux command line.
Typically, testing for a file returns 0 true if the file exists, and 1 false if the file does not exist. For some operations, you may want to reverse the logic. The exclamation point! This command makes sure there is not a file named test. You should see test. You can use a similar command for a directory — replace the —f option with —d :.
Similarly we use single brackets in this example to check if the directory is preset within shell script. In this example we will use test command to make sure if directory is present or not before we perform certain task.
In this example we will use single and double brackets in single line form to check for the directory. I would recommend using [[..
There are no shell attributes as I have used in all other examples and scenarios in this tutorial. But we do have some hacks which we can use to check if directory is empty or not- empty. In this example we will list the content of the directory, suppress the output and then based on the exit code check if the directory is empty or contains some content. We can use find command and then suppress the output to check if the target directory has some content or not. Again as I said since there is no easy way to check if a directory is empty or not using some attributes, we will list the content of the directory.
If you get no output then the directory is empty or else not empty. Similarly there are many more attributes which you can use with shell scripts to check for different file types, such as symbolic links, file permissions etc. Attributes What it does? 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.
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