修改原文件内容

open (READ,"<","/misc");
open (WRITE,"+<","/misc");
 while (my $text = )
 {
  if ($text =~ m/yyww/)
  {
   $text =~ s/yyww/aabb/;    ###将所有原件中的yyww内容替换为aabb
  }
  print WRITE $text;   
 }
close READ;
close WRITE;