(I was bit carried away...sry for my poor formating earlier)

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

In reply to Re^3: Exact string matching by Anonymous Monk
in thread Exact string matching by Anonymous Monk

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