fwrite schrijft over current content heen....

mode Description
'r' Open for reading only; place the file pointer at the beginning of the file.
'r+' Open for reading and writing; place the file pointer at the beginning of the file.
'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'a' Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
'a+' Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
'x' Create and open for writing only; place the file pointer at the beginning of the file. If the file already exists, the fopen() call will fail by returning FALSE and generating an error of level E_WARNING. If the file does not exist, attempt to create it. This is equivalent to specifying O_EXCL|O_CREAT flags for the underlying open(2) system call. This option is supported in PHP 4.3.2 and later, and only works for local files.
'x+' Create and open for reading and writing; place the file pointer at the beginning of the file. If the file already exists, the fopen() call will fail by returning FALSE and generating an error of level E_WARNING. If the file does not exist, attempt to create it. This is equivalent to specifying O_EXCL|O_CREAT flags for the underlying open(2) system call. This option is supported in PHP 4.3.2 and later, and only works for local files.

Opmerking: Op systemen die verschil maken tussen binair ('b') en tekst ('t') mode vertaling (zoals Windows), kan je achter de mode of de letter 'b' of de letter 't' neerzetten om de vertalings mode respectievelijk op binair of op tekst te zetten.

De standaard vertalings mode hangt af van de SAPI die je gebruikt, dus we moedigen je aan om altijd de vertalings mode aan te geven. Meestal zal dat de 'b' zijn, als je je script compatible over verschillende besturingssystemen wilt houden.

Als je niet de 'b' mode opgeeft als je werkt met binaire bestanden, dan kan je raar gedrag verwachten met je data, waaronder niet werkende afbeeldingsbestanden en rare problemen met rn tekens.

Het wordt sterk geadviseerd dat je altijd de 'b' mode gebruikt als je bestanden opent met fopen().