Re^2: Exact string matching

[Anonymous Monk]

Dear Monk, I'm so sorry for being very immature, this is my first time posting a question, so plz forgive my immaturity

open(HD,"file") or die ("Cant open");
$text=<HD>;
$text=~s/ //g;
chomp $text;

$pattern="word";
$offset = 0;

$pos=index $text,$pattern,$offset;

while ($pos != -1) 
{
    print "Found $pattern at $pos\n";
    $offset = $pos + 1;
        $pos = index($text, $pattern, $offset);

}

[ramprasad27]

Looking at what you are trying to achieve, here is the code

use Data::Dumper; 
open (HAN,'employee.pm');
 my $cont = <HAN>; # assume $cont = 'package Employee df df'; 
my %hash = (); 
while ( $cont =~ m/(\w+)/g )
{ $hash{$1}++;
 } 

print Dumper(\%hash); --------- output 
$VAR1 = { 
'Employee' => 1, 
'df' => 2, 
'package' => 1 };

it prints how many time each word occured ..

[Anonymous Monk]

Dear Ram, Thank you very much for your kind assistance but this works only if the words in the file is separated with a defined spacer such as a white space, what if the file contains only strings without any spacer (junk of characters or sequence of characters to be precise). That's where I am stuck. I need to find the number of occurrence of all possible substrings, that to in linear time (sry, that I was not clear). example: $text = 'howdoidoit' and the answer should be like, for substring of length 3 => how = 1 ; owd = 1 ; wdo = 1 ; doi = 2 ; oid = 1 ; ido = 1 ; oit = 1 ;