FAQ 5.28 How can I read a single character from a file? From the keyboard?

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5.28: How can I read a single character from a file?  From the keyboard?

    You can use the builtin "getc()" function for most filehandles, but it
    won't (easily) work on a terminal device. For STDIN, either use the
    Term::ReadKey module from CPAN or use the sample code in "getc" in

    If your system supports the portable operating system programming
    interface (POSIX), you can use the following code, which you'll note
    turns off echo processing as well.

        #!/usr/bin/perl -w
        use strict;
        $| = 1;
        for (1..4) {
            my $got;
            print "gimme: ";
            $got = getone();
            print "--> $got\n";

        BEGIN {
            use POSIX qw(:termios_h);

            my ($term, $oterm, $echo, $noecho, $fd_stdin);

            $fd_stdin = fileno(STDIN);

            $term     = POSIX::Termios->new();
            $oterm     = $term->getlflag();

            $echo     = ECHO | ECHOK | ICANON;
            $noecho   = $oterm & ~$echo;

            sub cbreak {
                $term->setcc(VTIME, 1);
                $term->setattr($fd_stdin, TCSANOW);

            sub cooked {
                $term->setcc(VTIME, 0);
                $term->setattr($fd_stdin, TCSANOW);

            sub getone {
                my $key = '';
                sysread(STDIN, $key, 1);
                return $key;


        END { cooked() }

    The Term::ReadKey module from CPAN may be easier to use. Recent versions
    include also support for non-portable systems as well.

        use Term::ReadKey;
        open(TTY, "</dev/tty");
        print "Gimme a char: ";
        ReadMode "raw";
        $key = ReadKey 0, *TTY;
        ReadMode "normal";
        printf "\nYou said %s, char number %03d\n",
            $key, ord $key;


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