#!/usr/bin/perl 
use warnings;
use strict;

my $file = "outtest.txt";
open OUT, ">>", $file || die("Cannot open file for output.\n");

my @array;
while(<DATA>) {
    s/tcp//g;
    @array = split(/\s+/, $_);
    print OUT "Address1=",$array[1],"\n";
    print OUT "Address2=",$array[2],"\n";
    print OUT "Address3=",$array[3],"\n";
}
__DATA__
tcp 20 tcp 40 tcp 80
[download]

<code>
C:\Code>perl outtest.pl
C:\Code>perl outtest.pl
C:\Code>type outtest.txt
Address1=20
Address2=40
Address3=80
Address1=20
Address2=40
Address3=80
[download]

moritz points out that it can be a bad idea to edit a file in place. Perl does, however, have a handy -i flag for in-place editing which, if given an extension, will preserve your original file with that extension, the modified file taking the original name. Given a spurious "tcp" file and an "address" file

$ cat spw638403.txt
aajkaj  XYZtcpHJHKtcpKJHKH
ashhgdasjh    JKHKJHtcpUUHtcpHDKJHtcpJHDJAHD
kjkjn  NHYtcpHHGJJH
$ cat spw638403.addr
Address1=
Address2=
Address3=
$
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running this code (note the -i.bak flag

#!/usr/bin/perl -i.bak
#
use strict;
use warnings;

my @list = ();

BEGIN
{
    my $inFile = q{spw638403.txt};
    open my $inFH, q{<}, $inFile
       or die qq{open: $inFile: $!\n};

    while ( <$inFH> )
    {
        chomp;
        push @list, ( split m{tcp}, ( split )[1] )[0];
    }

    close $inFH
       or die qq{close: $inFile: $!\n};
}

while ( <> )
{
    s{$}{$list[$. - 1]};
    print;
}
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with the address file as the argument results in the original file preserved as spw638403.addr.bak and the modified file as spw638403.addr

$ ./spw638403 spw638403.addr
$ cat spw638403.addr
Address1=XYZ
Address2=JKHKJH
Address3=NHY
$
[download]

I hope this is of use.

Cheers,

JohnGG

Update: Clarified point that the scripts needs the name of the file to be modified as an argument.

Update 2: Corrected senior moment with flag. It is, of course, the -i flag, not -p

What I'd suggest is that you create a new file with the desired content, and the move the new file to the place of the old file.

You could first read things that you want to append into @list, and then do the "real" operation:

use File::Copy; # for move()
open my $of, '<', $old_file or die "Can't read $old_file: $!";
open my $nf, '>', $new_file or die "Can't write $new_file: $!";
my $line_number = 0;
while (my $line = <$of>){
    chomp $line;
    print $nf $line, $list[$line_number];
}
close $nf;
close $of;
move $new_file, $old_file;
[download]

It's generally a bad idea to edit a file in place.

Is it? Why?

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

It's a bad idea to edit a file in-place without a backup, let's just put it that way. Creating a separate output file from your source means your source *is* the backup. So moritz's point, a little less succinctly put, is, "Don't edit a file with important data unless you can undo any changes."
(Or use version control.)

if line in appending file =$line[0], append $list[0], and so on...?

Certainly, you can read a file into an array, and process that; whether it's a good idea depends on the size of the file. For reasonably sized files (a few megabytes), it's likely to be the choice which uses the least wall-clock time. If the file is very large, something like Tie::File may be appropriate.

At least until you get the code debugged, I would make sure that you create a backup file when you do an "edit in place."

---

editorial corrections

---

emc

Information about American English usage here and here.

Any New York City or Connecticut area jobs? I'm currently unemployed.

$ cat target-file.txt
Address1=
Address2=
Address3=

$ perl -Mstrict -pi -wle 'our @ports; BEGIN { my $source = "tcp 20 tcp
+ 40 tcp 80"; @ports = $source =~ /tcp\s+(\d+)/g;} $_ .= shift(@ports)
+;'  target-file.txt

$ cat target-file.txt
Address1=20
Address2=40
Address3=80
[download]

$ cat target-file.txt
Address1=
Address2=
Address3=

$ perl -Mstrict -wnle 'our @ports; BEGIN { my $source = "tcp 20 tcp 40
+ tcp 80"; @ports = $source =~ /tcp\s+(\d+)/g;} $_ .= shift(@ports); p
+rint' target-file.txt  > output.txt

$ cat output.txt
Address1=20
Address2=40
Address3=80

$ cat target-file.txt
Address1=
Address2=
Address3=
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I'll try to use Tie::File

use Tie::File;
#.......your code
#at this point you have
#@ports with port numbers
#and file address.txt which you need to append

tie @addresses, 'Tie::File', "address.txt" or die $!;
for my $position (0..$#ports) {
    $addresses[$position] .= $ports[$position];
}
untie @addresses;
[download]

But you may combine reading of the ports file and updating addresses file (with $. magick).

If all the lines in your first file look like those in the sample, why not just read the second file (the one with the port numbers) and build the first file from scratch?

I think some more information about the first file (Address1=, etc) may be in order, as I suspect there is much more to this file than has been revealed.

There's a lot more to the file where I get the port number from, I just used an example, but here's a more descriptive example of the file I pull the port out of: example.txt:, line from example txt:
entry_entry_host_entry 8080/tcp # hostname entry entry