Shell Programming and Scripting

#!/usr/bin/perl -w
# arrayref for columns
my $cols = [];
# counter for characters
my $counter = 0;
# get file handle
open FILE, "<in.txt";
# iterate over lines in file
foreach my $line (<FILE>)
{
	# remove line feed
	chomp($line);
	# create array containing each char on line
 	my @chars = split(//,$line);
 	# create arrayref for characters
 	$cols->[$counter]=[];
 	# iterate over characters, pushing each into an
 	# index of the arrayref just created
 	for my $char (@chars)
 	{
 		push(@{$cols->[$counter]},$char);
 	}
 	# iterate the counter for the next line
 	$counter++;
}
# close the file handle
close FILE;

# open a new file handle for output
open OUT, ">output.txt";
# iterate over the columns (0 thru max index of array storing characters at index 0)
for my $i ( 0 .. @{$cols->[0]} -1)
{
	# iterate over the lines (0 thru max index of array storing lines)
	for my $j ( 0 .. @$cols -1 )
	{
		# print character at line $j, column $i
		print OUT $cols->[$j]->[$i];
	}	
	# print linefeed
	print OUT "\n";
}
# close the filehandle
close OUT;

#!/usr/bin/perl -w

my $cols = [];
my $counter = 0;
open FILE, "<in.txt";
foreach my $line (<FILE>)
{
	chomp($line);
 	my @chars = split(//,$line);
 	$cols->[$counter]=[];
 	for my $char (@chars)
 	{
 		push(@{$cols->[$counter]},$char);
 	}
 	$counter++;
}
close FILE;

open OUT, ">output.txt";
for my $i ( 0 .. @{$cols->[0]} -1)
{
	for my $j ( 0 .. @$cols -1 )
	{
		print OUT $cols->[$j]->[$i];
	}	
	print OUT "\n";
}
close OUT;

awk '{if(NF > MAX) MAX = NF;for(x=0;++x<=NF;)a[x,NR]=$x}END{for(y=0;++y<=MAX;){for(z=0;++z<=NR;) {if ((y,z) in a) printf a[y,z]; else printf " "};print ""}}' FS= file