> Gunnar Hjalmarsson wrote:
>
> David Greenberg wrote:
> > #!/usr/bin/perl
> > use strict;
> > open (GROUPFH, "<File1");
> > my @groups = ();
> > while (my $line = <GROUPFH>) {
> > chomp ($line);
> > push (@groups, $line);
> > }
> > close (GROUPFH);
> > open (USERFH, "File2");
> > my %group_to_users = ();
> > while (my $line = <USERFH>) {
> > chomp ($line);
> > my ($user, @user_groups) = split ('\s+', $line);
> > for my $group (@user_groups) {
> > push (@{$group_to_users{$group}}, $user) if
> $group_to_users{$group};
> > $group_to_users{$group} = [$user] unless
> $group_to_users{$group};
> > }
> > }
> > close (USERFH);
> > for my $group (@groups) {
> > print $group . ":\n";
> > for my $user (@{$group_to_users{$group}}) {
> > print $user . "\n";
> > }
> > print "\n";
> > }
>
> Or a little shorter:
>
> #!/usr/bin/perl
> use strict;
> use warnings;
> open my $GROUPS, 'File1' or die $!;
> open my $USERS, 'File2' or die $!;
>
> my %groups;
> chomp and $groups{$_} = [] for <$GROUPS>;
>
> while ( <$USERS> ) {
> my ($user, @groups) = split;
> $groups{$_} and push @{ $groups{$_} }, $user for @groups;
> }
>
> for ( sort keys %groups ) {
> print "$_:\n", ( join "\n", @{ $groups{$_} } ), "\n\n";
> }
>
> __END__
>
It seems to me that Olakunle Banjo shall not be an Perl Expert.
Can you also explain him the code?
Note: Usually is good policy closeing the opened files.
Marcos
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
<http://learn.perl.org/> <http://learn.perl.org/first-response>
