Read and update a file

File I/O & Php

Reading a File and updating it

Copy and paste the following code into your editor and run it (code comments are included).
If you want to see the live result, try it here (new window).

This example actually updates the file according to a date and a number; if the line contains the current date, it increments the number otherwise it adds another line with the current date.
Everyday a line is then added and a new counter is initiated.

The source code:
<html> <body> <? $date=date("Y-m-d"); $file='file.txt'; $bool=0; $number=0; $bigstr=''; $first=''; /*Open the file for reading*/ $handle = @fopen($file, "r"); if($handle) { while (!feof($handle) && !$bool) { //http://www.php.net/manual/en/function.fgets.php (get line from file pointer) $buffer = fgets($handle); if(strpos($buffer,$date) === FALSE) { //if we did not find an occurence, we append the line to the variable $bigstr.=$buffer; } else { //http://www.php.net/sscanf - we browse the buffer for a string followed by a number sscanf($buffer,"%s %d",$first,$number); echo 'Line found with number: '.$number.' '; $number++; //we did find a line for the date of today $bool=1; } } fclose($handle); } /*If we did not find a match, we update the file by adding a new line*/ if(!$bool) { if (!$handle = fopen($file, 'a')) { //can not open the file echo 'Can not open file - line 50'.' '; } else { if(fwrite($handle,"\n".$date.' '.$number) === FALSE) { //can not write/append to file echo 'Can not write/append to file - line 58'.' '; } else echo 'Line appended to file. '; fclose($handle); } } else { /*If found a match, we update the corresponding line*/ if (!$handle = fopen($file, 'w')) { //can not open file for writing echo 'Can not open file for writing - line 73'; } else { if(fwrite($handle,$bigstr.$date.' '.$number) === FALSE) { //can not write to file echo 'Can not write to file - line 81'.' '; } else { echo 'Line written into file <a href="file.txt">file.txt</a>.'.' '; } fclose($handle); } } ?> </body> </html>

Notes:
- the file is automatically created if it does not exists (see writing into a file for more details);
- you need to have the necessary permissions to be able to write into a file on your server (see chmod on linux/unix).

You may wish to read additional materials from:
- http://www.php.net/manual/en/function.fgets.php
- http://www.php.net/sscanf

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