## 例

`

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

`

## 説明

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.

## 戻り値

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