basename—with a directory name delivers portions of the pathname
basename string [ suffix ] dirname string
basename deletes any prefix ending in / (forward slash) and the suffix (if present in string) from string, and prints the result on the standard output.
1 basename /usr/local/bin 2 scriptname="`basename $0`"
Strips off the prefix /usr/local/ and displays bin.
Assigns just the name of the script, $0, to the variable scriptname.