I think your problem stems from the backslashes in your replace pattern. It's really hard (at least for me) to figure out how many times to escape in double quotes which will then be interpreted by the shell (do I need two backslashes here or four? More?). I have a feeling you might have needed 4 backslashes there, but there's a better way to do what you want...

You call sed like this: 

  system("sed -e 's/$search/$replace/g' $File1 > $Replace_html");

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This is generally considered a bad and very unsafe way, not to mention at times unpredictable. What if $search, $replace, or any other variable has the value ";; rm -rf / ;;" ? What will the command line be equivalent to? You should call external programs using a method that does not use the shell, or automatically espaces arguments. May I suggest: 
  open (my $fh, "-|", 'sed', '-e', "s/$search/$replace/g", $File1);
  my $new_file = do { local $/; <$fh> }; # grab sed's output

  # now you can write the contents of $new_file to a file yourself.

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This open call executes sed with the arguments you want, and sends its output back do the filehandle $fh. You don't have to worry about the shell messing up the characters in the arguments, because this mechanism bypasses the shell, making it very safe.

Another alternative would be to use IPC::Open2 or IPC::Open3, which will let you execute a command in the same safe way as above, and send its output to the file all in one statement. But I'll leave that as an assignment for you -- it's a very similar mechanism, however.

Also, the next time you submit a question (or an answer?) that contains code, use <code> tags, and check the previews of your post to make sure they look readable! Hey, is there an echo in here? ;)

blokhead

In reply to Re: need help on SED by blokhead
in thread need help on SED by Anonymous Monk

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