in reply to Re: Arrow Keys
in thread Arrow Keys

After cobbling some stuff together, I got this working. Hope it helps someone else. Bill 
#!/usr/bin/perl -w

use strict;
use warnings;

use IO::Handle;

eval {
    my $stdin = new IO::Handle;
       $stdin->fdopen( fileno( STDIN ), "r" ) || die "Cannot open STDIN";

    system "stty -icanon -isig -echo min 1 time 0";

    while ( my $char = $stdin->getc() ) {
        print "Up\n"     if ( ord( $char ) == 65 );  # up
        print "Down\n"   if ( ord( $char ) == 66 );  # down
        print "Right\n"  if ( ord( $char ) == 67 );  # right arrow
        print "Left\n"   if ( ord( $char ) == 68 );  # left arrow
        print "Return\n" if ( ord( $char ) == 10 );  # return key
        print "Delete\n" if ( ord( $char ) == 127 ); # delete key
        print "Esc\n"    if ( ord( $char ) == 27 );  # escape key
        print "Tab\n"    if ( ord( $char ) == 9 );   # tab key
        next             if ( ord( $char ) == 32 );  # skip on space key
        last             if ( $char =~ /q/ );        # break on q
        last             if ( $char =~ /\003/ );     # break on Ctrl-C
        last             if ( $char =~ /\032/ );     # break on Ctrl-Z
        print "ord: " . ord($char) . "\n";
    }
    system "stty icanon echo isig";
    exit(0);
};

if ( $@ ) {
    print "$@\n";
    system "stty icanon echo isig";
    exit(1);
}

Replies are listed 'Best First'.
Re^3: Arrow Keys
by idbill (Initiate) on May 27, 2009 at 18:42 UTC
    heh... I posted the last bit of code, but wanted to mention that I have not found a good source for the escape codes (\###). Bill
[reply]
      Ok...

      getc() is getting each 'character' at a time... when you do control keys and function keys, they appear to be made up of more than one character.

      So the script has to keep track of the sequence of characters to figure out what key was actually pressed.

      (Note, this works for xterm-color on OS X)

      Below is the new code: 
      #!/usr/bin/perl -w

use strict;
use warnings;

use IO::Handle;

eval {
    my $stdin = new IO::Handle;
       $stdin->fdopen( fileno( STDIN ), "r" ) || die "Cannot open STDIN";

    system "stty -icanon -isig -echo min 1 time 0";
    my $escape;
    my $ctrl;
    my $function;

    while ( my $char = $stdin->getc() ) {

        if ( ord( $char ) == 27 ) {             # Escape character
            $escape = 1;
            print "ESC + ";
            next;
        }
        if ( $escape && ord( $char ) == 91 ) {  # Control character
            $ctrl = 1;
            print "CTRL + ";
            next;
        }

        if ( $escape && $ctrl && $function && ord( $char ) == 126 ) {
            undef $escape;                      # Clean up after Fnctn key
            undef $ctrl;
            undef $function;
            next;
        }

        if ( $escape && $ctrl && !$function ) {
            print "Up\n"     if ( ord( $char ) == 65 );  # up
            print "Down\n"   if ( ord( $char ) == 66 );  # down
            print "Right\n"  if ( ord( $char ) == 67 );  # right arrow
            print "Left\n"   if ( ord( $char ) == 68 );  # left arrow
            if ( ord( $char ) == 49 ) {                  # Function character
                $function = 1;
                print "FCN + ";
            } else {                                     # Clean up for arrow keys
                undef $escape;
                undef $ctrl;
            }
            next;
        }

        if ( $escape && $ctrl && $function ) {
            print "F5\n"     if ( ord( $char ) == 53 ); # F5 key
            print "F6\n"     if ( ord( $char ) == 55 ); # F6 key
            print "F7\n"     if ( ord( $char ) == 56 ); # F7 key
            print "F8\n"     if ( ord( $char ) == 57 ); # F8 key
                                                        # wait for clean up char
            next;
        }

        if ( $escape && !$ctrl && !$function ) {
            print "F1\n" if ( ord( $char ) == 80 );  # F1 key
            print "F2\n" if ( ord( $char ) == 81 );  # F2 key
            print "F3\n" if ( ord( $char ) == 82 );  # F3 key
            print "F4\n" if ( ord( $char ) == 83 );  # F4 key
            undef $escape;                           # Clean up
            next;
        }

        print "Return\n" if ( ord( $char ) == 10 );  # return key
        print "Delete\n" if ( ord( $char ) == 127 ); # delete key
        print "Tab\n"    if ( ord( $char ) == 9 );   # tab key
        next             if ( ord( $char ) == 32 );  # skip on space key
        last             if ( $char =~ /q/ );        # break on q
        last             if ( $char =~ /\003/ );     # break on Ctrl-C
        last             if ( $char =~ /\032/ );     # break on Ctrl-Z
        print "ord: " . ord($char) . "\n";
    }
    system "stty icanon echo isig";
    exit(0);
};

if ( $@ ) {
    print "$@\n";
    system "stty icanon echo isig";
    exit(1);
}
[reply]
      Looking at: http://www.AsciiTable.com/
      it would appear my code is invalid... still looking.
[reply]

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