FREAD(3) 1 FREAD(3)
fread - Binary-safe file read
SYNOPSIS
string fread (resource $handle, int $length)
DESCRIPTION
fread(3) reads up to $length bytes from the file pointer referenced by $handle. Reading stops as soon as one of the following conditions is
met:
o$length bytes have been read
o EOF (end of file) is reached
o a packet becomes available or the socket timeout occurs (for network streams)
o if the stream is read buffered and it does not represent a plain file, at most one read of up to a number of bytes equal to the
chunk size (usually 8192) is made; depending on the previously buffered data, the size of the returned data may be larger than the
chunk size.
PARAMETERS
o $handle
-A file system pointer resource that is typically created using fopen(3).
o $length
- Up to $length number of bytes read.
RETURN VALUES
Returns the read string or FALSE on failure.
EXAMPLES
Example #1
A simple fread(3) example
<?php
// get contents of a file into a string
$filename = "/usr/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>
Example #2
Binary fread(3) example
Warning
On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in
fopen(3) mode parameter.
<?php
$filename = "c:\files\somepic.gif";
$handle = fopen($filename, "rb");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>
Example #3
Remote fread(3) examples
Warning
When reading from anything that is not a regular local file, such as streams returned when reading remote files or from
popen(3) and fsockopen(3), 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("http://www.example.com/", "rb");
$contents = stream_get_contents($handle);
fclose($handle);
?>
<?php
$handle = fopen("http://www.example.com/", "rb");
if (FALSE === $handle) {
exit("Failed to open stream to URL");
}
$contents = '';
while (!feof($handle)) {
$contents .= fread($handle, 8192);
}
fclose($handle);
?>
NOTES
Note
If you just want to get the contents of a file into a string, use file_get_contents(3) as it has much better performance than the
code above.
Note
Note that fread(3) reads from the current position of the file pointer. Use ftell(3) to find the current position of the pointer
and rewind(3) to rewind the pointer position.
SEE ALSO
fwrite(3), fopen(3), fsockopen(3), popen(3), fgets(3), fgetss(3), fscanf(3), file(3), fpassthru(3), ftell(3), rewind(3).
PHP Documentation Group FREAD(3)