Deleting one entry from a flat file

[Glenn]

I have a script that allows a flat file to be viewed in a table from a text file, submittedequipment.txt. Each entry in the text file also provides a button to click that will add the entry that goes with it to a second text file, usedequipment.txt. When the entry is added to the second text file I also want it to be deleted from the first text file without deleting the whole file.

I've tried using session variables and if statements as well as creating a hidden form to pass on data, but have had no luck.

Anyone have any code that would do this or suggestions on a direction to go?

thanks

[spstieng]

Don't think there's an easy way of doing this.
One solution is that you read each line into an array.
Then compare each element with the line of text you want to remove.

When you find a match, delete the element and save the array to a text file.

I think my theory should work :-)

[ivory]

I have an array called $lines ( = file('somedata.txt'); ) and I want to remove one element. I know which because I also have variable called $which, telling me the index of the offending line in $lines.

$s=array;
foreach($lines as $n=>$v)
  if($n!=$which)
    $s[]=$v;

Now $s is all the things that $lines is, minus the $which-th. Open somedata.txt and overwrite what was there. Next time somedata.txt is read into $lines, $lines will be one entry smaller.

[majiclab]

ivory's idea should work, however on larger files it might take a while. Another possibility would be to simply unset() the line $which.

unset($lines[ $which ]);

This will remove that line.

Hope that helps.

-Percy