Compare two files and output match

Question

I have files similar to this:

File1:

1.1.1.7 mounting of udf filesystems is disabled Fail
1.1.1.8 mounting of FAT filesystems is disabled  Fail
1.1.5 noexec option set on /tmp partition   Fail
1.1.17 noexec option set on /dev/shm partition  Fail
1.1.21 sticky bit is set on all world-writable directories  Fail
1.3.1 AIDE is installed Fail

File2:

1.1.1.7 Ensure mounting of udf filesystems is disabled
1.1.1.8 Ensure mounting of FAT filesystems is disabled
1.1.3 Ensure nodev option set on /tmp partition
1.1.4 Ensure nosuid option set on /tmp partition

I want to compare the two files on the first column and output where they match. For the content above, the output would be:

1.1.1.7 Ensure mounting of udf filesystems is disabled
1.1.1.7 mounting of udf filesystems is disabled Fail
1.1.1.8 Ensure mounting of FAT filesystems is disabled
1.1.1.8 mounting of FAT filesystems is disabled  Fail

How would I do this?

Also how would I reverse it so I can show those that have no match? Comparing File1 to File2 and vice versa?

steeldriver · Accepted Answer · 2017-07-06T12:58:15.737

awk '
  NR == FNR {a[$1] = $0; next} 
  ($1 in a) {print; print a[$1]}
' File1 File2
1.1.1.7 Ensure mounting of udf filesystems is disabled
1.1.1.7 mounting of udf filesystems is disabled Fail
1.1.1.8 Ensure mounting of FAT filesystems is disabled
1.1.1.8 mounting of FAT filesystems is disabled  Fail

If you want to do a simple test for non-matching entries in File2

awk 'NR==FNR {a[$1]=$0; next} !($1 in a)' File1 File2
1.1.3 Ensure nodev option set on /tmp partition
1.1.4 Ensure nosuid option set on /tmp partition

and conversely non-matching entries in File1

awk 'NR==FNR {a[$1]=$0; next} !($1 in a)' File2 File1
1.1.5 noexec option set on /tmp partition   Fail
1.1.17 noexec option set on /dev/shm partition  Fail
1.1.21 sticky bit is set on all world-writable directories  Fail
1.3.1 AIDE is installed Fail

(the print is implicit).

Thanks. Is there an easy way to reverse it so I can show those that have no match? Comparing File1 to File2 and vice versa? — Proletariat, Jul 06 '17 at 12:25

score 0 · Answer 2 · answered Jul 06 '17 at 12:23

perl -lane '
        @ARGV and $h{$F[0]}=$_,next;
        print "$_\n$h{$F[0]}" if exists $h{$F[0]};
' File2 File1

1.1.1.7 mounting of udf filesystems is disabled Fail
1.1.1.7 Ensure mounting of udf filesystems is disabled
1.1.1.8 mounting of FAT filesystems is disabled  Fail
1.1.1.8 Ensure mounting of FAT filesystems is disabled

Compare two files and output match

2 Answers2