In Bash, you can use the nullglob option to verify if any files with a specific pattern exist in a directory or not. The nullglob option causes the shell to expand patterns to an empty list if no matches are found. Here’s how you can use the nullglob option to verify if *.c files exist in a directory:
- Open a terminal and navigate to the directory you want to check.
- Set the
nullgloboption using the following command:shopt -s nullglob
- Use the
lscommand to list all the*.cfiles in the current directory. If there are no files, the output will be empty.ls *.c
- If there are files, you can use them in your script or further processing.
- After you are done checking, unset the
nullgloboption to avoid unexpected behavior:shopt -u nullglob
For example, if you want to check if there are any *.c files in the /home/user/code directory, you can use the following commands:
cd /home/user/code
shopt -s nullglob
if [ -n "$(ls *.c)" ]; then
echo "C files found!"
else
echo "No C files found."
fi
shopt -u nullglob
This will check if any *.c files exist in the /home/user/code directory and output a message accordingly.