note 70715 added to function.feof

feof() is, in fact, reliable. However, you have to use it carefully in conjunction with fgets(). A common (but incorrect) approach is to try something like this: <? $fp = fopen("myfile.txt", "r"); while (!feof($fp)) { $current_line = fgets($fp); // do stuff to the current line here } fclose($fp); ?> The problem when processing plain text files is that feof() will not return true after getting the last line of input. You need to try to get input _and fail_ before feof() returns true. You can think of the loop above working like this: * (merrily looping, getting lines and processing them) * fgets used to get 2nd to last line * line is processed * loop back up -- feof returns false, so do the steps inside the loop * fgets used to get last line * line is processed * loop back up -- since the last call to fgets worked (you got the last line), feof still returns false, so you do the steps inside the loop again * fgets used to try to get another line (but there's nothing there!) * your code doesn't realize this, and tries to process this non-existent line (typically by doing the same actions again) * now when your code loops back up, feof returns true, and your loop ends There's two ways to solve this: 1. You can put an additional test for feof() inside the loop 2. You can move around your calls to fgets() so that the testing of feof() happens in a better location Here's solution 1: <? $fp = fopen("myfile.txt", "r"); while(!feof($fp)) { $current_line = fgets($fp); if (!feof($fp)) { // process current line } } fclose($fp); ?> And here's solution 2 (IMHO, more elegant): <? $fp = fopen("myfile.txt", "r"); $current_line = fgets($fp); while (!feof($fp)) { // process current line $current_line = fgets($fp); } fclose($fp); ?> FYI, the eof() function in C++ works the exact same way, so this isn't just some weird PHP thing... ---- Server IP: 64.71.164.2 Probable Submitter: 147.144.3.239 ---- Manual Page -- http://www.php.net/manual/en/function.feof.php Edit -- https://master.php.net/note/edit/70715 Del: integrated -- https://master.php.net/note/delete/70715/integrated Del: useless -- https://master.php.net/note/delete/70715/useless Del: bad code -- https://master.php.net/note/delete/70715/bad+code Del: spam -- https://master.php.net/note/delete/70715/spam Del: non-english -- https://master.php.net/note/delete/70715/non-english Del: in docs -- https://master.php.net/note/delete/70715/in+docs Del: other reasons-- https://master.php.net/note/delete/70715 Reject -- https://master.php.net/note/reject/70715 Search -- https://master.php.net/manage/user-notes.php