">" and ">>" are pipelines.

For Perl and bash (one of the linux shells) ">" is the standard way to say: "redirect this stuff to the named file and overwrite (delete) its previous contents with this".

And ">>" is the standard way to say: "add this material after the last line of the file (updating this contents) but preserve any previous contents that you found in this file". ">>" works also in perl and in bash

If the file is missing both do basically the same. Create a "box" (the file) and dump all the "bricks" into this box.

So, let's see what are you doing:

 open (HAN , ">" ,'D:\RAM\perl\test') or die "$!"; 
# DELETE the contents of this file and open it
while (<HAN>){
 s/e/\*\*/ig; 
# nothing here to mach, the file is empty, no survivor "e" chars
 print HAN ; 
# thus, nothing is changed and nothing left to print to the file
}

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In reply to Re^3: opening file for editing by pvaldes
in thread opening file for editing by ramprasad27

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