As holli suggested you can make use of the above methods.

The string you have mentioned seems to be a path name, if it is so, you can make use of File::Basename.

use File::Basename;
$str='/usr/local/prj/code/prog/prog1';
$name = basename("$str");
print "$name";
[download]

output:prog1

update: added, use File::Basename;