$ perl -Mstrict -Mwarnings -le 'print qq{Enter a 9-character line:}; my $line = <>; chomp $line; if ( $line eq reverse $line ) { print q{yes}; } else { print q{no}; }'
Enter a 9-character line:
123456789
no
$ perl -Mstrict -Mwarnings -le 'print qq{Enter a 9-character line:}; my $line = <>; chomp $line; if ( $line eq reverse $line ) { print q{yes}; } else { print q{no}; }'
Enter a 9-character line:
123454321
yes