(PHP 5 >= 5.1.0, PHP 7)
SplFileObject::ftruncate — Truncates the file to a given length
$size
)
Truncates the file to size bytes.
sizeThe size to truncate to.
Note:
If
sizeis larger than the file it is extended with null bytes.If
sizeis smaller than the file, the extra data will be lost.
成功时返回 TRUE， 或者在失败时返回 FALSE。
Example #1 SplFileObject::ftruncate() example
<?php
// Create file containing "Hello World!"
$file = new SplFileObject("/tmp/ftruncate", "w+");
$file->fwrite("Hello World!");
// Truncate to 5 bytes
$file->ftruncate(5);
// Rewind and read data
$file->rewind();
echo $file->fgets();
?>
以上例程的输出类似于：
Hello