Php/docs/splfileobject.fseek

• PHP Manual
• SplFileObject
• Seek to a position

SplFileObject::fseek

(PHP 5 >= 5.1.0, PHP 7)

SplFileObject::fseek — Seek to a position

说明

public SplFileObject::fseek ( int $offset [, int $whence = SEEK_SET ] ) : int

Seek to a position in the file measured in bytes from the beginning of the file, obtained by adding offset to the position specified by whence.

参数

offset

The offset. A negative value can be used to move backwards through the file which is useful when SEEK_END is used as the whence value.

whence

whence values are:

• SEEK_SET - Set position equal to offset bytes.
• SEEK_CUR - Set position to current location plus offset.
• SEEK_END - Set position to end-of-file plus offset.

If whence is not specified, it is assumed to be SEEK_SET.

返回值

Returns 0 if the seek was successful, -1 otherwise. Note that seeking past EOF is not considered an error.

范例

Example #1 SplFileObject::fseek() example

<?php$file = new SplFileObject("somefile.txt");// Read first line$data = $file->fgets();// Move back to the beginning of the file// Same as $file->rewind();$file->fseek(0);?>

参见

• fseek() - 在文件指针中定位