Another way using the reduce() function in List::Util. List:Util is a core module so you don't have to install it. If more than one "max", prints the first one. 
#!/usr/bin/perl -w
use strict;
use List::Util qw(reduce);

while (<DATA>)
{
   chomp;
   my (@array) = split';',$_;
   
   my $ColumnNumber = 
      reduce { $array[$a] >= $array[$b] ? $a : $b } 1..@array-1; 
      
   print $ColumnNumber, "\n";  
}

=prints
3
3
2
=cut

__DATA__
id001;10;10;30
id002;30;20;50
id003;30;80;10

[download]

In reply to Re: Find column number for the row-wise max value by Marshall
in thread Find column number for the row-wise max value by jaksow

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