In some cases that you have hundred of thousands or even million of files in a directory that you want to delete, you will encounter this error:
/bin/rm: Argument list too long.
The problem is when you type command like rm -rf *, * is replaced with the list of all files, and usually the memory buffer allocated to shell is small to accomodate let's say million of file names.
To solve this issue, I usually use this simple command:
find . -type f -delete