Is there away for me to compare 2 files with out using c/c++ python, java, etc.. maybe only using bash/awk? see the thing is that I need to loop through 2 files and compare each user with each file to see if they are there... if not than do something with the user? Now I prefer to do this in c++ but my job doesn't want me to do this because of the limited knowledge in c++ that stands in were I work at, so... ya, now If I have no other choice than I will create it in c++.

i.e:

file one
compare it with file two
loop trough the user names on both files and see if the user name
exist on both file.

There are several tools for this sort of thing:

• diff - compare files line by line
• cmp - compare two files byte by byte
• join - join lines of two files on a common field

Note that join requires that the two input files be sorted on the join fields.

It depends on the layout of the file. If they're both just a list of user names, you could sort and use diff or sdiff to compare them. If the username is part of other data on each line, can you post a sample? Tools like cut can pull fields out of a line.

See also comm, sdiff

Have a look at what kompare does. It is a nice graphical diff that can give a good overall view, depending on how many modifications have been done.
Usually I use tkdiff.

I use vimdiff (Vi advanced).
Also,Araxis Merge is a good tool which you can try out.