If you are not increasing or decreasing the number of characters in the line, the following example may work: 
open( FILE, "+<", $fileName ) or die "can't open file: $!";

while( <FILE> )
{
   if( s/foo/bar/g )
   {
      seek( FILE, -(length), 1 ) or die "can't seek: $!";
      print FILE;
   }
}

[download]

Alternatively, you could read the entire file into a variable, perform your substitutions, seek to the beginning of the file, and write the contents of the variable to the file.

In reply to Re^3: Edit Macintosh file, keeping resource fork by eieio
in thread Edit Macintosh file, keeping resource fork by forrest

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