Php/docs/function.gzseek

• PHP Manual
• Zlib 函数
• Seek on a gz-file pointer

gzseek

(PHP 4, PHP 5, PHP 7)

gzseek — Seek on a gz-file pointer

说明

gzseek ( resource $stream , int $offset [, int $whence = SEEK_SET ] ) : int

Sets the file position indicator for the given file pointer to the given offset byte into the file stream. Equivalent to calling (in C) gzseek(zp, offset, SEEK_SET).

If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; gzseek() then compresses a sequence of zeroes up to the new starting position.

参数

stream

The gz-file pointer. It must be valid, and must point to a file successfully opened by gzopen().

offset

The seeked offset.

whence

whence values are:

• SEEK_SET - Set position equal to offset bytes.
• SEEK_CUR - Set position to current location plus offset.

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

返回值

Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.

范例

Example #1 gzseek() example

<?php$gz = gzopen('somefile.gz', 'r');gzseek($gz,2);echo gzgetc($gz);gzclose($gz);?>

参见

• gztell() - Tell gz-file pointer read/write position
• gzrewind() - Rewind the position of a gz-file pointer