If I have string { I_love_shell_scripts}
anyone knows how to have output {stpircs_llehs_evol_I}
by using shell and perl ?I know in perl, there is reverse() funcation, but
can it be done by not using reverse()?

Looks like homework. Is it? May be you should solve this one on your own.

this had been already posted

you should have tried with the search option

here is the link

could u please make a try!!!

reversing a string

Of course yes. This is simple enough. Are you ready to try it on your own?

My implementation is a subroutine that contains only 3 statements using a recursive scheme. This is one way.

Another way: you can always find the length() of the string, so you know the largest character position is 1 less than that value, then write a loop to read each character backwards with substr().