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ftruncate

(PHP 4, PHP 5, PHP 7, PHP 8)

ftruncate — Truncates a file to a given length

Description

ftruncate(resource $stream, int $size): bool

Takes the filepointer, stream, and truncates the file to length, size.

Parameters

stream

The file pointer.

Note:

The stream must be open for writing.

size

The size to truncate to.

Note:

If size is larger than the file then the file is extended with null bytes.

If size is smaller than the file then the file is truncated to that size.

Return Values

Returns true on success or false on failure.

Examples

Example #1 File truncation example

<?php
$filename = 'lorem_ipsum.txt';

$handle = fopen($filename, 'r+');
ftruncate($handle, rand(1, filesize($filename)));
rewind($handle);
echo fread($handle, filesize($filename));
fclose($handle);
?>

Notes

Note:

The file pointer is not changed.

See Also

© 1997–2025 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.ftruncate.php