Adding text to the top of the file!

Anon

I am having the problem I'm sure many have had before. I'm trying to set up a news posting system where the user inputs some things into some forms, clicks and clicks post. The script below is then supposed to update a text file with the new news. The problem is, I can only get the new news to overwrite (w+) or go below (a) the bottom of the old news. Feel free to change this script, or write me a new one - just help me! 🙂

$today = date("m.j.y g:iA");
$newstotal="<h6>$news_subject - $user_name $today</h6><p>$news</p>";

$data = file("default.news"); // file you want insert line into
$c = count($data); // count existing lines
$fp = fopen("default.news", 'w+'); // open the file for writing
fwrite($fp, $newstotal); // this is where it would add your 'entry'
for($i=0; $i<$c;$i++){ // write back the old data
fwrite($fp, $data);
}
fclose($fp); // close up the file

printf("News posted successfully.");

kparker

Geez, I just wrote a quick description of how to do this--it seems like just a few days ago, but could have been a week or more. Anyway, I was going to just refer you to it, but darned if I can find it via any search!

Anon

Well the script I posted was actually a script I found on a PHP website. It doesn't work though! I also derived my own way of doing it before I went out looking for scripts, but it didn't work either!

The only way I can think to do it is to copy the contents of one file into a temporary file (tmpfile()😉 then go ahead and overwrite the old news with the new news, and then continue overwriting the old news with the information copied over from the tmp file. Unfortunately, I haven't found a way to do this =(

Any help is appreciated!

Jason

kparker

OK, time to reinvent my own wheel :-) ( frodo -- see below )

But first, the script you posted has one obvious error:

   fwrite($fp, $data);

Clearly, this should refer to $data[$i]--i.e. an individual element of the array.

But the problem with the above is that there's no locking, so two or more instances could be trying to do this at the same time.

If I recall correctly, here's what I did before (warning--omits most error checking!):

   $filename = 'somefile.txt';

   $fp = fopen( $filename, 'r+' );
   flock( $fp, 2 );
   for ($i = 0; $data[$i] = fgets( $fp, 65000 ); $i++ )
      {
      }

   rewind( $fp );
   fwrite( $fp, "$newdata\n");
   for ($i = 0; $i < sizeof($data); $i++ )
      {
      fwrite( $fp, $data[$i] . '\n' );
      }

   flock( $fp, 3 );
   fclose($fp);

Note this only works with inserts: if you try to use it to delete a line from a text file, you'll end up with extra text at the end, measuring the exact length of the line that was deleted.

Now, here's a unique, arbitrary keyword that I can use to search for this posting in the future: frodo (I also put this in the top in case the keyword indexing only does the first N lines.)