(PHP 4, PHP 5, PHP 7)
ftruncate — 将文件截断到给定的长度
$handle
, int $size
) : bool
接受文件指针 handle 作为参数，并将文件大小截取为
size。
handle文件指针。
Note:
The
handlemust be open for writing.
sizeThe size to truncate to.
Note:
If
sizeis larger than the file then the file is extended with null bytes.If
sizeis smaller than the file then the file is truncated to that size.
成功时返回 TRUE， 或者在失败时返回 FALSE。
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);
?>
Note:
The file pointer is not changed.