chmod
Changes file permissions on one or more files.
Changes the permissions of each listed file to MODE. The first argument is the numeric mode (typically given as an octal literal); the remaining arguments are file paths. Returns the number of files successfully changed. Preserves file-type bits (S_IFMT) from the existing mode and replaces only the permission bits (lower 12 bits).
Synopsis
chmod 0755, $file1, $file2;
chmod 0644, @files;
my $count = chmod 0600, glob("*.conf");