Shell Programming and Scripting

How about

Code:

awk 'NR == 1 {for (n=split($0, T); n; n--) F1[T[n]]; next} !($1 in F1)' file[12]
10
10
200
200
50

diff reports differences between two files and what has to happen to change the first file into the second. If a record appears in the first file but not the second, diff reports the line(s) on the first file a d and the line where they used to be on the 2nd file

A record on the 2nd file but not the first, a a reports the line number of the first file and the records added.

File 1 contains (actually 1 per line) 1 3 5 9 10 11 12 23 48 and
File 2 contains (actually 1 per line) 2 4 6 8 9 yy 10, the output from diff will be

Code:

1,3c1,4
< 1
< 3
< 5
---
> 2
> 4
> 6
> 8
4a6
> yy
6,9d7
< 11
< 12
< 23
< 48

Only lines starting with ">" or "<" appear in one file but not the other. You should never have a change where you have both symbols and a "---" line.

@wbport thanks for the explanation, but this solution would require more data handling so I'll go with the other one

@RudiC, this works but may I ask if I understood the code well: