Re: How to conditionally substitute in files?

Siegfried Heintze (Aditi) wrote:
> 
>> From: John W. Krahn [mailto:[email protected]]
>> 
>> You have to code it that way explicitly yourself, something like (UNTESTED):
>> 
>> my $file = 'Migration.cs';
>> 
>> open my $IN,  '<', $file       or die "Cannot open '$file' $!";
>> open my $OUT, '>', "$file.new" or die "Cannot open '$file.new' $!";
>> 
>> my $changed;
>> while ( <$IN> ) {
>>      $changed += s/class/xybpublicabc/g;
>>      print $OUT;
>>      }
>> 
>> close $OUT;
>> close $IN;
>> 
>> if ( $changed ) {
>>      rename $file, "$file.bak" or die "Cannot rename '$file' $!";
>>      rename "$file.new", $file or die "Cannot rename '$file.new' $!";
>> else {
>>      unlink "$file.new" or die "Cannot unlink '$file.new' $!";
>>      }
> 
> Thanks John!
> I to edit it a little but it works!
> 
> Can someone explain to why I have to remove the $ from $IN and $OUT
> and remove the "my" in "my $IN" and "my $OUT" to make it work?

Older versions of Perl could not use lexical variables for filehandles.



John
-- 
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