Shell Programming and Scripting

Hello,
I need to add information in the gecos of each login in the passwd file. I have expect installed. I thought about using expect to to read a file with the login names and the gecos information and then execute the command passwd with the -f option. The other option would be to read the passwd file and split the login at the first letter (ie: jyoung > j young) and then placing that in the gecos part. This is on AIX 5.2. Does anyone have a script that would do this or someting similar that I could modify. Thank you.

Ok, I have create a Perl script that I believe will do the job. Could some of you take a look at it and let me know if you see any problems? Also if I replace the passwd file in etc with the output from this what types of problems might I have.

Code:

#!/usr/bin/perl
open (users,"</law1/passuser") or die ("Cannot open passuser");
while (<users>) {
      ($uname,$x,$uid,$gid,$gecos,$home,$shell) = split ':', $_;
      if (length($gecos)==0)
         {
          $first_l=substr($uname,0,1);
          $gecos_l=length($uname)-1;
          $second_l=substr($uname,1,$gecos_l);
          $full_n=$first_l . " " . $second_l;
         }
      else
         {$full_n=$gecos;}
       print "$uname:$x:$uid:$gid:$full_n:$home:$shell";
}

I still have some tweaking to do, but I thought before I go any farther I would have you take a look. When I run the script I will redirect the output to a file. Thank you.