regex for <STDIN> 3

[AIXFinder]

print "Enter sequences for rows: ";
$a = <STDIN>;
chop $a;
print "Enter sequences for cols: ";
$b = <STDIN>;
chop $b;

I want to allow only certain characters (W, X, Y, Z) for the inputs for both of <STDIN>.
If any other characters than W, X, Y, Z are entered, it asks until the correct sets of characters are entered.
Also, the input converts to upper case regardless lower or upper cases entered for the characters (W, X, Y, Z, w, x, y, z).

thx much

 

[Kirsle]

my $a = '';
my $b = '';
until ($a !~ /[^WXYZ]/) {
   print "Enter sequences for rows: ";
   chomp ($a = <STDIN>);
   $a = uc($a);
}
until ($b !~ /[^WXYZ]/) {
   print "Enter sequences for cols: ";
   chomp ($b = <STDIN>);
   $b = uc($b);
}

Useful modules for this kind of thing:
IO:rompt
Term:rompt

-------------
Cuvou.com | The NEW Kirsle.net

 

[AIXFinder]

thx so much

 

[KevinADC]

AIXFinder,

you should find these links helpful:

http://perldoc.perl.org/

http://www.perl.org/books/beginning-perl/

------------------------------------------
- Kevin, perl coder unexceptional!

 

[MillerH]

Eeek! Don't use "$a" and "$b" for variable names. Those are special variables used by the sort function.

http://perldoc.perl.org/perlvar.html

http://perldoc.perl.org/functions/sort.html

Also, you might as well make a function for inputting if this is going to be a repeated request.

my $x = promptWXYZ("Enter sequences for rows: ");
my $y = promptWXYZ("Enter sequences for cols: ");

print "x = '$x', y = '$y'\n";

sub promptWXYZ {
	my $prompt = shift;
	my $input;
	do {
		print $prompt;
		chomp ($input = <STDIN>);
	} until ($input =~ /^[WXYZ]+$/i);
	return uc $input;
}

 

[AIXFinder]

thx so much