one base converter for all bin/oct/dec/hex

b2

#!/usr/bin/perl

if (@ARGV < 2) {
  printf("Convert numbers among bin/oct/dec/hex\n");
  printf("\nUsage: b2 2/8/10/16 num num2 ... \n");
  exit;
}

for ($i=1; $i<@ARGV; $i++) {
  if ($ARGV[0] == 2) {
        $num = oct("0b$ARGV[$i]");
  } elsif ($ARGV[0] == 8) {
        $num = oct($ARGV[$i]);
  } elsif ($ARGV[0] == 10) {
        $num = $ARGV[$i];
  } elsif ($ARGV[0] == 16) {
        $num = hex($ARGV[$i]);
  } else {
        printf("Usage: b2 2/8/10/16 num num2 ... \n");
        exit;
  }
  printf("0x%x = 0d%d = 0%o = 0b%b\n", $num, $num, $num, $num);
}