in reply to trying to decide best data structure for problem at hand.

I'd key by name then uid:

use strict;
use warnings;

my %entries;
my $key;
my $host;

while (<DATA>) {
     chomp;
     next if ! length;
     
     if (m|^/|) {
          $host = $_;
     } elsif (/(\w+)\s+(\d+)\s+(\d+)\s+(.*)/) {
          my ($name, $uid, $gid, $gecos) = ($1, $2, $3, $4);
          
          $entries{$name}{$uid} = { # User data keyed by uid
                    gid => $gid,
                    gecos => $gecos,
                    host => $host,
               };
     } else {
          print "Can't parse >$_<\n";
     }
}

my @unlike = grep {keys (%{$entries{$_}}) > 1} keys %entries;

print "@unlike";

__DATA__
/var/tmp/passwd.hostname1.platform

nguyenhe 1929 20 Henry Nguyen,555-555-555
bjose 1990 20 Bobby Jose,x3338

/var/tmp/passwd.hostname2.platform

vjain 2098 20 Vineet Kumar Jain, offshore
llai 2122 20 Levius Lai
bjose 1995 20 Bobby Jose,x3338

[download]

Prints:

bjose

[download]
DWIM is Perl's answer to Gödel

Replies are listed 'Best First'.
Re^2: trying to decide best data structure for problem at hand.
by mikejones (Scribe) on Jan 03, 2007 at 21:50 UTC
    wow cannot believe I did not see how simple it really was. Anyway thank you, but in your code you do not use 
    $entries{$name}{$uid} = { # User data keyed by uid
                    gid => $gid,
                    gecos => $gecos,
                    host => $host,

    [download]
    gid => $gid, gecos => $gecos, host => $host ???
[reply]
[d/l]

      It's there because in your OP you say "... I need to identify on what host each user-id ...". It's not used because I didn't need it to illustrate the main issue. However if you change the final print to:

      for my $name (@unlike) {
    my @hosts = map {$entries{$name}{$_}{host}} keys %{$entries{$name}
+};
    print "$name found on \n\t", join ("\n\t", @hosts), "\n\n";
}

      [download]

      then the output is:

      bjose found on 
    /var/tmp/passwd.hostname2.platform
    /var/tmp/passwd.hostname1.platform

      [download]
      DWIM is Perl's answer to Gödel
[reply]
[d/l]
[select]
        I don't understand this logic or data structure, but I will attempt to explain it in English. 
        for every element in array unlike (which is username)
map keys values from hash entries to ??? with name and host.  Assign t
+his to the array hosts.

        [download]
        I understand the print statement, but the data structure build I do not. 
        Why do you need keys %{$entries{$name} and why not just 
keys %{$entries}?

        [download]
        I would like to see output like so or something to that effect:
I tried adding values uid and gecos but got errors and played for awhi
+le and could not get it printed correctly.
So you are using name and uid as the keys and host,gecos and gid as va
+lues?
I seem to struggle with hashes even though I have read Learning and Pr
+ogramming Perl. Any advice you have?
 
wlprdadm found with uids of 134 and 135 on
        /home/dbsmith/passwd.eipdbmp1.hpux $gecos
        /home/dbsmith/passwd.carappp1.hpux $gecos

as an example.

thank you!

        [download]
[reply]
[d/l]
[select]

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