How to print duplicate entries on same line 1

[uuperl]

Hi,
I have the following input file:

user1:staff
user1:mis
user2:finance
user2ayroll
user3:hr
user4:engineer
user4:IT
user5:facility

How to print the above input file to output file as:
user1:staff,mis
user2:finance,payroll
user3:hr
user4:engineer,IT
user5:facility

Any help or suggestion will be appreciated. Thanks in advance!

 

[KevinADC]

what have you tried so far?

 

[InDenial]

read the file line by line
split on the :
put it in a hash with key = userx and value = right side of the :
check with each line if the key already excists and if so.. add the new value to the end of the excisting value belonging to the existing key.

 

[uuperl]

here is what i tried so far and seems not working correctly.

#!/usr/bin/perl

$input = "input.dat";

open(inputfile,"$input") or die "Can not open file: '$input' $!\n";
while(<inputfile>) {
chop;
($user,$group) = split(/:/);
$input_index{$user} = $_;
$value = $group;
if (exists $input_index{$user}) {
print "$user,$value\n";
}
else {
print "$user,$value\n";
}
}
close(inputfile);

 

[KevinADC]

InDenial has given you one way to do it:

my $input = "input.dat";
my %input_index = ();
open(inputfile,"$input") or die "Can not open file: '$input' $!\n";
while(<inputfile>) {
   chop;
   my ($user,$group) = split(/:/);
   if (exists $input_index{$user}) {
      $input_index{$user} .= ",$group";
   }
   else {
      $input_index{$user} = $group;
   }
}
close(inputfile);
for my $users (sort keys %input_index) {
   print "$users:$input_index{$users}\n";
}

that is not how I would do it but it works OK and there is nothing wrong with doing it that way. I would build a hash of arrays for a more flexible data structure:

my $input = "input.dat";
my %input_index = ();
open(inputfile,"$input") or die "Can not open file: '$input' $!\n";
while(<inputfile>) {
   chop;
   my ($user,$group) = split(/:/);
   push @{$input_index{$user}},$group; 
}
close(inputfile);
for my $users (sort keys %input_index) {
   print "$users:",join(',', sort @{$input_index{$users}}),"\n";
}

 

[uuperl]

Thanks KevinADC, you are the best!!!!!

 

[uuperl]

also thanks to InDenial !!