fwrite

WMPRO, WMMINI FW >= 1.0 WMMEGA FW >= 2.0

Write data to a file, stream or socket

This function performs a binary-safe write of strings or bytes specified by integers to a previously opened resource¹⁾

$handle: Valid handle of a previously opened resource

$data: The string, int or array data to be written in one of the following forms:

• string - A string to write
• int - A single byte to write specified as an integer (8 bits, decimal 0-255)²⁾
• array - A series of string and/or int byte data to write - useful for writing several strings and/or binary data to a resource³⁾

$length: Optional length of buffer - automatically calculated for strings if not specified

Integer number of bytes successfully written

0 if no bytes were written⁴⁾

-1 for socket errors (reset, connection broken)⁵⁾

<?
  $fh = fopen("/fwrite_test.txt","w");
  if (!$fh) {
    print("File open failed");
  } else {
    $result =fwrite($fh,"Line 1");
    $result+=fwrite($fh,13);
    $result+=fwrite($fh,10);
    $result+=fwrite($fh,array(65,66,67,68,69,70,13,10,"Line 3",13,10));
    print($result." bytes were written to the file");
    fclose($fh);
  }
?>

The above example will display:

24 bytes were written to the file

And the above example will create the file /fwrite_test.txt containing:

Line 1
ABCDEF
Line 3

When working with binary data such as data read from a file using fread(), make sure to pass the variable as a pointer using the & symbol. Otherwise a copy of the string will be made but will only be copied until the first NULL character is found.

For example, this script will make an exact copy of the contents of file original.bin into copy.bin:

<?
  $fo = fopen("/original.bin","r");
  $fh = fopen("/copy.bin","w");
  $len = filesize($fo);
  while ($len) {
     if ($len>512) {
       $buflen=512;
     } else $buflen=$len;
     $data = fread($fo,512);
     // make sure you also specify the optional file size 
     // or else it will use the length of the string (till the first null).
     // also, pass the variable by reference
     fwrite($fh,&$data,512);
     $len = $len - $buflen;
  }
  fclose($fh);
  fclose($fo);
?>

fopen() - Open a file for reading or writing

fseropen() - Open the serial port at the specified baud rate with optional parameters

f485open() - Open the RS-485 port at the specified baud rate and parity

fsockopen() - Open an internet socket connection with optional timeout

fread() - Read bytes from a file, stream or socket

fgets() - Return a single line from a file, stream or socket, with optional size limit

feof() - Test if no more data is available in a file, stream or socket

filesize() - Return the size of a file, or the number of unread bytes in a stream or socket

fseek() - Position the file pointer in an open file

ftell() - Return the current position of a file read/write pointer

fclose() - Close a file, stream or socket