my $winsize = "\0" x 8;

# XXX: should be require sys/ioctl.pl
# value below is for BSD, eg: OpenBSD, darwin=MacOS X, (etc?)

my $TIOCGWINSZ = 0x40087468;
if (ioctl(STDOUT, $TIOCGWINSZ, $winsize)) {
    ($rows, $cols, $xpix, $ypix) = unpack('S4', $winsize);
} else {
    $cols = 80;
}

print "$cols\n";

__END__
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <termios.h>

main() {
    struct winsize mywinsize;
    int ttyfd;

    if ((ttyfd = open("/dev/tty", O_RDWR|O_NOCTTY)) == -1) {
        perror("open /dev/tty");
        exit(-1);
    } 

    if (ioctl(ttyfd, TIOCGWINSZ, &mywinsize) == -1) {
        perror("ioctl TIOCGWINSZ");
        exit(-1);
    } 

    printf("TIOCGWINSZ %#08x\n",            TIOCGWINSZ             );
    printf("sizeof struct winsize %d\n",    sizeof(struct winsize) );
    printf("rows %d\n",                     mywinsize.ws_row       );
    printf("cols %d\n",                     mywinsize.ws_col       );

    if (fclose(stdout) == EOF) {
        perror("close stdout");
        exit(-1);
    } 

    exit(0);
}