truncate - shrink or extend the size of a file to the specified size

To Clear contents of a file with truncate
$ truncate -s 0 example.txt

To truncate a file to a specific size
$ truncate -s 200K example.txt

To extend file size
$ truncate -s +400K example.txt

To reduce file size
$ truncate -s -100k example.txt



regards,
T.Dhanasekar