use File::Basename to do this job

use File::Basename;

$file1 = 'C:\test\abc.txt';

$file2 = 'C:\test\file2.txt';

$file3 = 'P:\cool\file3.txt';

$file1=basename($file1);
$file2=basename($file2);
$file3=basename($file3);

print "$file1\n";
print "$file2\n";
print "$file3\n";
[download]

Output

abc.txt
file2.txt
file3.txt
[download]