I have two comma delimited files that I need to compare and have the differences written to a third csv file. Basically I have a csv file of 10,000 students that started the semester, after drop date I now have a second csv file with only 9000 students that are still enrolled. I need an output file, in the same format as the first two, that lists the 1000 or so students that dropped so I can remove the accounts. A lot of information has changed for each user, passwords, expiration dates, so the only reliable field for comparison is "id" but I still need the whole line printed out in a new file. An example below.
First file
id,lastname,firstname,defaultserver,password,expiration
1524781,Anderson,Jon,srv01,jon,12-05-02.
1843552,Bruford,William,srv01,william,12-17-02.
7589243,Howe,Steven,srv01,steven,12-05-02.
0547629,Squire,Chris,srv01,chris,12-05-02.
5486135,Wakeman,Rick,srv01,rick,12-17-02.

Second file.
id,lastname,firstname,defaultserver,password,expiration.
1524781,Anderson,Jon,srv01,jon,12-05-02.
1843552,Bruford,William,srv01,william,12-17-02.
0547629,Squire,Chris,srv01,chris,12-05-02.
Output file.
id,lastname,firstname,defaultserver,password,expiration.
7589243,Howe,Steven,srv01,steven,12-05-02.
5486135,Wakeman,Rick,srv01,rick,12-17-02.

I have many problems like this, and I have heard PERL is excellent with files, so I am looking into learning it to manage these tasks. Any help would be greatly appreciated.

In reply to file comparison by gasky

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