Bash Loop Script to join lines while a field is unchanged

[derekwnek]

Trying to bash script the following with no luck at all. Please help. THANKS!

Convert a file that has random usernames with a varing number of multiple random IP's on multiple lines to one line per username with all of the IP's on the same line:

Ex:
Convert this:

usernameA,10.19.43.67
usernameA,172.19.240.5
usernameA,192.168.4.3
usernameB,10.23.14.8
usernameB,172.22.22.14

To this:

usernameA,10.19.43.67,172.19.240.5,192.168.4.3
usernameB,10.23.14.8,172.22.22.14

[derekwnek]

awk '
BEGIN {
RS = "[\t\n\v\f\r ]*[\n\r][\t\n\v\f\r ]*"
FS = ",[\t\v\f ]*"
users = 0
}

(NF > 1) {
if (!($1 in list)) {
user[++users] = $1
list[$1] = ","
}
for (i = 2; i <= NF; i++)
if (length($i) > 0)
if (!index(list[$1], "," $i ","))
list[$1] = list[$1] $i ","
}

END {
for (u = 1; u <= users; u++) {
thisuser = user[u]
thislist = list[thisuser]
sub(/^,+/, "", thislist)
sub(/,+$/, "", thislist)
printf("%s:%s\n", thisuser, thislist)
}
}' filename

[three18ti]

Here's my crack at it in Perl...

#!/usr/bin/perl
use strict;
use warnings;

my %users;
open my $FHIN, '<', $ARGV[0];
foreach (<$FHIN>){
  my ($user, $ip) = split/,/;
  $users{$user} .= ",$ip";
}

print "$_$users{$_} \n" foreach keys %users;