while(<FH>) {
    
my $inp_word4 = $_;

my $data = 'undef';
    
@inp_word=split(//,$inp_word4);
    
for(my $i=0;$i<@inp_word;$i++)
{

if (($inp_word[$i]=~m/(n)/i) && ($data eq 'undef') ){
$data =$1;
 next;
}
if (($inp_word[$i] =~ m/(a)/i) && ( $data eq 'n')){
$data = $data.$1;
next;
}
            
if (($inp_word[$i] =~ m/(m)/i) && ( $data eq 'na')){
$data = 'undef';
$inp_word[$i] = '+d';
next;
            
}
}

print  @inp_word  ;    
 
}

[download]

i have tested for the test cases "name domr fame naming namnam nanaming " and it's working.you can still make the code smaller.

in your code the if statement can never become true , your trying to match single character say 'n' with 'na'

In reply to Re: replace a character based on rule file by nithins
in thread replace a character based on rule file by lakssreedhar

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.