ubuntu command to epmty a file code example

Example 1: bash command to empty textfile

: > file.log

Example 2: rm directory linux

To remove an empty directory, use either rmdir or rm -d followed by the directory name: 
rm -d dirname rmdir dirname.
To remove non-empty directories and all the files within them, use the rm command with the -r (recursive) option: 
rm -r dirname.