#!/usr/bin/python
import sys
if len(sys.argv) != 3:
    print "Usage: " + sys.argv[0] + "file1 file2";
    sys.exit(-1);
file1 = sys.argv[1]
file2 = sys.argv[2]
list1 = {};
for line in open(file1):
    list1[line.split()[0]] = 1;
for line in open(file2):
    key = line.split()[0];
    if key not in list1:
        sys.stdout.write(line)

#!/bin/sh
if [[ $# < 2 ]];then
    echo "Usage: $0 file1 file2"
    exit
fi
function do_diff()
{
    if [[ $# < 2 ]];then
        echo "Usage: $0 file1 file2"
        return 1
    fi
    if [[ ! -f $1 ]];then
        echo "$1 is not file"
        return 2
    fi
    if [[ ! -f $2 ]];then
        echo "$2 is not file"
        return 3
    fi
    awk '
        BEGIN{FS=OFS=" "}
        ARGIND == 1 {
            arr[$1] = 1;
        }
        ARGIND == 2 {
            if (!($1 in arr)) {
                print $0;
            }
        }
    ' $1 $2
}
do_diff $1 $2


#!/usr/bin/perl -w
exit if (1 > $#ARGV);
my %map_orig;
my $file_orig = shift @ARGV;
open FH, "<$file_orig" or die "can't open file: $file_orig";
while (<FH>) {
        chomp;
        #$map_orig{$_} = 1;
        my ($filed) = split /\s+/;
        $map_orig{$filed} = 1;
}
close (FH);
my $file_diff = shift @ARGV;
open FH, "<$file_diff" or die "can't open file: $file_diff";
while (<FH>) {
        chomp;
        my ($filed) = split /\s+/;
        print "$_\n" if (!defined$map_orig{$filed});
}
close (FH)