Merge CSV file using Perl - windows

Question

I have a CSV file that I need to merge using the following Perl code, but I am not able to run it. It is supposed to out put multiple text files, but it is not working.
#!/usr/local/bin/perl
#
$template_file_name="rtr-template.txt";
while(<>) {
($location, $name, $lo0ip, $frameip, $framedlci, $eth0ip, $x)
= split (/,/);
open(TFILE, "< $template_file_name") || die "config template file $template_file_name:
$!\n";
$ofile_name = $name . ".txt";
open(OFILE, "> $ofile_name") || die "output config file $ofile_name: $!\n";
while (<TFILE>) {
s/##location##/$location/;
s/##rtrname##/$name/;
s/##eth0-ip##/$eth0ip/;
s/##loop0-ip##/$lo0ip/;
s/##frame-ip##/$frameip/;
s/##frame-DLCI##/$framedlci/;
printf OFILE $_;
}
}
The CSV file looks like this
Toronto, Router1, 172.25.15.1, 172.25.16.6,101, 172.25.100.1
And this the rtr-template.txt file
!
version 12.1
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname ##rtrname##
!
enable password cisco
enable secret cisco
!
interface Loopback0
ip address ##loop0-ip## 255.255.255.255
!
interface Serial0/0
description Frame-Relay Circuit
no ip address
encapsulation frame-relay
ip route-cache policy
frame-relay lmi-type ansi
no shutdown
!
interface Serial0/0.1 point-to-point
ip address ##frame-ip## 255.255.255.252
frame-relay interface-dlci ##frame-DLCI##
!
interface FastEthernet0/1
description User LAN Segment
ip address ##eth0-ip## 255.255.255.0
no shutdown
!
router eigrp 99
network 172.25.0.0
!
snmp-server location ##location##
!
line con 0
password cisco
login
transport input none
line aux 0
password cisco
login
line vty 0 4
password cisco
login
transport input telnet
!
end

Answer 1

The main problem is that you're running your program by double-clicking on its file name in Windows Explorer.
The way <> works is that it will read from any files that you specify on the command line (that appear in the #ARGV array) or, if that array is empty, then it will read from STDIN — usually the keyboard.
Double-clicking the file gives it no command-line parameters, so it waits for you to type input in the black window that appears. That means you've entered <RTR-DATA.CSV as input to your while loop and Perl has tried to split it on commas, giving only a single field, so it sets $location to <RTR-DATA.CSV. Not what you wanted!
So, if you run your program from the cmd window by entering
create-configs.pl RTR-DATA.CSV
then within the program #ARGV will contain RTR-DATA.CSV and the <> will automatically read from that file
Here are some further notes on your code
There is no need for the #! line on a Windows system, which will normally have the .pl file extension tied to the perl executable
You must always use strict and use warnings at the top of every Perl program you write, and declare all your variables at their first point of use. That would have given some very strong clues about the nature of your problem
You should normally chomp each line read from a file, as it will have a newline character at the end that can cause problems if you leave it at the end of the last field returned by split
In this case you should also probably add optional whitespace either side of the comma in the pattern you are splitting on, so as to remove leading and trailing spaces from the fields it returns
You should always use lexical file handles ($out_fh instead of OFILE) with the three-parameter form of open
And here's a rewrite of your code that takes into account all of those points. I hope it helps
use strict;
use warnings;
my $template_file = 'rtr-template.txt';
while ( <> ) {
chomp;
my ($location, $name, $lo0ip, $frameip, $framedlci, $eth0ip) = split /\s*,\s*/;
open my $t_fh, '<', $template_file
or die qq{Unable to open "$template_file" for input: $!};
my $out_file = "$name.txt";
open my $out_fh, '>', $out_file
or die qq{Unable to open "$out_file" for output: $!};
while (<$t_fh>) {
s/##location##/$location/g;
s/##rtrname##/$name/g;
s/##eth0-ip##/$eth0ip/g;
s/##loop0-ip##/$lo0ip/g;
s/##frame-ip##/$frameip/g;
s/##frame-DLCI##/$framedlci/g;
printf $out_fh $_;
}
}

Answer 2

Use Text::CSV to parse the CSV file and Template Toolkit or similar to do the templating. Don't reinvent the wheel.