Pull specific information from a long list with Perl

Question

The file that I've got to work with here is the result of an LDAP extraction but I need to ultimately get the information formatted over to something that a spreadsheet can use.

So, the data is as follows:

DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
displayName: John Doe
name: ##userName

DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
displayName: Jane Doe Jr
name: ##userName

DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
DataDataDataDataDataDataDataDataDataDataDataDataDataDataDataData
displayName: Ted Doe
name: ##userName

The format that I need to export to is:

firstName lastName userName
firstName lastName userName
firstName lastName userName

Where the spaces are tabs so I can then impor that file into a database. I have experience doing this in VBScript but I'm trying to switch over to using Perl for as much server administration as possible.

I'm not sure on the syntax for what I want which is basically

while not endoffile{
detect "displayName: " & $firstName & " " & $lastName
detect "name: ##" & $userName

write $firstName tab $lastName tab $userName to file
}

Also if someone could point me to a resource specifically on the text parsing syntax that Perl uses, I'd be very grateful. Most of the resources that I've come across haven't been very helpful.

Also, some of the userNames are numbers. The leading two numbers still need to be trimmed but the userName is always 6 characters long if that helps.

Answer 1

Something like this should do the trick -- it reads from stdin and outputs to stdout, so you can use normal unix pipes to use files:

#!/usr/bin/perl

use strict;
use warnings;
use String::Util 'trim';

# set "line ending" to \n\n, to allow slurping by paragraphs:
local $/ = "\n\n";

while (my $line = <>)
{
    chomp $line;

    my ($displayName) = ($line =~ /^displayName: (.+)$/m);
    my ($name) = ($line =~ /^name: ##(.+)$/m);
    trim $displayName;
    trim $name;

    my ($firstName, $lastName) = ($displayName =~ /^([^ ]+) (.+)$/);

    print "$firstName\t$lastName\t$name\n";
}

I tested this using the sample input you gave below, as test.pl < input.txt and got the output:

John    Doe     userName
Jane    Doe     userName
Ted     Doe     userName

You can read about slurping in paragraph mode in perldoc perlvar under $/, or at this SO question (link needed). Matching within multiple lines is enabled with the m flag on the match operator -- see perldoc perlre.

Answer 2

This is my solution.

use strict;
use warnings;
my $fh;
my $file_contents;
my @info;
open $fh, '<', "data" or die($!);
local $/ = undef;
$file_contents = <$fh>;

while($file_contents =~ /.ame: (.*?)$(.*?).ame: (.*?)$/smg)
{

   my $displayname = $1;
   my $username = $3;
   $displayname =~ s/^\s+//; #clean off any whitespace from front/back
   $displayname =~ s/\s+$//;
   my ($firstname, $lastname) = split(/\s+/, $displayname); #split on whitespace

   print "$firstname\t$lastname\t$username\n"; #note the tabs
}