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fread

(PHP 4, PHP 5)

fread — Binary-safe file read

Beskrivelse

string fread ( resource $handle , int $length )

fread() reads up to length bytes from the file pointer referenced by handle . Reading stops as soon as one of the following conditions is met:

  • length bytes have been read
  • EOF (end of file) is reached
  • a packet becomes available (for network streams)
  • 8192 bytes have been read (after opening userspace stream)

Parameterliste

handle

A file system pointer resource that is typically created using fopen().

length

Up to length number of bytes read.

Returneringsværdier

Returns the read string or FALSE in case of error.

Eksempler

Example#1 A simple fread() example

<?php
// get contents of a file into a string
$filename "/usr/local/something.txt";
$handle fopen($filename"r");
$contents fread($handlefilesize($filename));
fclose($handle);
?>

Example#2 Binary fread() example

Warning

On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen() mode parameter.

<?php
$filename 
"c:\\files\\somepic.gif";
$handle fopen($filename"rb");
$contents fread($handlefilesize($filename));
fclose($handle);
?>

Example#3 Remote fread() examples

Warning

When reading from anything that is not a regular local file, such as streams returned when reading remote files or from popen() and fsockopen(), reading will stop after a packet is available. This means that you should collect the data together in chunks as shown in the examples below.

<?php
// For PHP 5 and up
$handle fopen("https://www.example.com/""rb");
$contents stream_get_contents($handle);
fclose($handle);
?>
<?php
$handle 
fopen("https://www.example.com/""rb");
$contents '';
while (!
feof($handle)) {
  
$contents .= fread($handle8192);
}
fclose($handle);
?>

Notes

Note: If you just want to get the contents of a file into a string, use file_get_contents() as it has much better performance than the code above.