1. if ($num % 2) { # This is an odd num
2. Use the same loop for both files, like:

   foreach (0 .. $#lines) {
       # print from file A
       # print from file B
   }
   [download]

3. Have you tried it out?

------
/me wants to be the brightest bulb in the chandelier!

Vote paco for President!

if ($num % 2 == 0) {
    #even
}
else {
    #odd
}
[download]

2) you'll probably have to use the eof() instead of < >

while(!eof(FILE1) && !eof(FILE2) {
   my $file1 = <FILE1>;
   my $file2 = <FILE2>;
}
[download]

3) if localized it will alter the subsiquent reads for only that pass through the loop.

my @eol = ("\n","\t","\r"); # etc, etc
while(<FILE>) {
    local $/ = shift @eol;
    my $line = <FILE>;
}
[download]

/\/\averick
perl -l -e "eval pack('h*','072796e6470272f2c5f2c5166756279636b672');"

1. Use the modulus operator (perlop).
2. What about using one loop and putting the statements after each other. Pseudocode:

   open File1
   open File2
   while (condition) {
     if (read from File1) {
       do something
     }
     if (read from File2) {
       do something;
     }
   }
   [download]

3. Have you tried it? What does it do?

-- Hofmator

my $counter = 0;

while(1)
{
        print "Got an even number\n" if(($counter++%2) == 0);
}
[download]

2) is a bit harder. I'm sure there are many elegant solutions. Some probably got posted while I was looking into it. My first try, if the files aren't too big, would be to slurp them into arrays and then fold them together.

use strict;
use warnings;

open (T1, "t1") or die;
my @file1 = <T1>;
my @file2 = <DATA>;
my @file;

while (@file1 and @file2) {
  push @file, (shift @file1, shift @file2);
}

push @file, @file1 or @file2; #catch any leftover

while (my $line = shift @file) {
   #do 'things' with it
    print $line;
}

__END__
file1
file1
file1
file1
[download]

Useless use of private array in void context at junk line 13.
file2
file1
file2
file1
file2
file1
file2
file1
file2
file3, kidding... file2
[download]

There's probably a more elegant solution, but this is what comes to mind.

3) Did you try it? I just ran the code you posted (cleaned up with ';' :-) and got this

use strict;
use warnings;

$/ = "****";

my @array;

while (<DATA>) {
     chomp;
     push @array, $_;
     $/= "####";
}

print "@array";

__END__
stuff****more
stuff####less
[download]

$ perl junk
stuff more
stuff less
[download]

Hope this helps
Ira

"So... What do all these little arrows mean?"
~unknown

# store files in arrays
open(A,'file_a');
my @a = (<A>);
close(A);

open(B,'file_b');
my @b= (<B>);
close(B);

# now the fun obfu bit
my $max =  [ @b + 0 => @a + 0 ] -> [ @b + 0 <= @a + 0 ];

for (0 .. $max) {
  print $a[$_] . $b[$_];
}
[download]

cLive ;-)

This sounds like a job for the evil 'goto'...

use strict;
use warnings;

open (T1, "t1") or die;

my $line;
my $flag = 1;
my $counter;

DATA:
while (<DATA>) {
    print;
    goto T1;
}

T1:
while (<T1>) {
    print;
    goto DATA;
}

__END__
file1
file1
file1
file1
[download]

This prints...

file1
file2
file1
file2
file1
file2
file1
file2
file2
file3, kidding... file2
[download]

Ira,

"So... What do all these little arrows mean?"
~unknown

In the spirit of TMTOWTDITDUG, here's my idea:

#!/usr/bin/perl -w
use strict;

my ($fh1, $fh2);
open $fh1, "file1.dat" or die "I no read file 1.\n";
open $fh2, "file2.dat" or die "I no read file 2.\n";

my $mainfh = $fh1;
while (<$mainfh>) {
   print;
   $mainfh = ($mainfh == $fh1) ? $fh2 : $fh1;
}
[download]

file1.dat:

I'm
sure
this
[download]

file2.dat:

pretty
that
works.
[download]

And finally, output:

I'm
pretty
sure
that
this
works.
[download]

His Royal Cheeziness