while () { my $line = $_; #### while (my $line = ) { #### $juris1 = substr( $line, 99, 1 ); $juris2 = substr( $line, 148, 1 ); $juris1 = "9"; $juris2 = "Z"; #or # #substr( $line, 99, 1, '9' ); # 4th argument replaces #substr( $line, 148, 1, 'Z' );# selected sub-string