Question

I have to replace all the keys in a hash with its respective hash values. This operation is performed in a file.

Below is my code:

my $file= 'IFandENDIF.txt';
my $bak= "$file.bak";
rename $file, $bak or die "cannot rename $file into $bak: $!";

open( my $in,  '<', $bak)  or die "cannot open $bak: $!";
open( my $out, '>', $file) or die "cannot create $file: $!";

while( <$in>)
{ 
    s/if(exists(%replstr))/$replstr{$1}/xeg;    
    print {$out} $_;   
}

close $in; 
close $out;

Please guide me on this.

Answer 1

To replace all instances of keys with hash values:

while ( my $line = <$in> ) {

    $line =~ s/$_/$replstr{$_}/g for keys %replstr;
    print $out $line;
}

Note that the /e modifier treats the replacement as code, not the pattern