Your issue is that once you have the literal $ character in your replacement string, you must run the string through an eval in order to get Perl to interpret the variable. You could accomplish this with the code 

my $data =  '#define MANUFACTURER   "xyz"';
my $replace = '#define MANUFACTURER(\s+)"xyz"';
my $replace_with =  '"#define MANUFACTURER$1\"abcd\""';

$data =~ s/$replace/$replace_with/eeg;

print $data;

[download]

See Search and replace in perlretut for a bit more detail. Note this should not be done if the data in $replace_with is at all untrustworthy.

In reply to Re: Problem with Pattern matching and substitution using variables by kennethk
in thread Problem with Pattern matching and substitution using variables by shtihskar

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