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   _llseek    ( 2 )

переместить смещение файла чтения / записи (reposition read/write file offset)

Имя (Name)

_llseek - reposition read/write file offset


Синопсис (Synopsis)

#include <sys/syscall.h> /* Definition of SYS_* constants */ #include <unistd.h>

int syscall(SYS__llseek, unsigned int fd, unsigned long offset_high, unsigned long offset_low, loff_t *result, unsigned int whence);

Note: glibc provides no wrapper for _llseek(), necessitating the use of syscall(2).


Описание (Description)

Note: for information about the llseek(3) library function, see lseek64(3).

The _llseek() system call repositions the offset of the open file description associated with the file descriptor fd to the value

(offset_high << 32) | offset_low

This new offset is a byte offset relative to the beginning of the file, the current file offset, or the end of the file, depending on whether whence is SEEK_SET, SEEK_CUR, or SEEK_END, respectively.

The new file offset is returned in the argument result. The type loff_t is a 64-bit signed type.

This system call exists on various 32-bit platforms to support seeking to large file offsets.


Возвращаемое значение (Return value)

Upon successful completion, _llseek() returns 0. Otherwise, a value of -1 is returned and errno is set to indicate the error.


Ошибки (Error)

EBADF fd is not an open file descriptor.

EFAULT Problem with copying results to user space.

EINVAL whence is invalid.


Стандарты (Conforming to)

This function is Linux-specific, and should not be used in programs intended to be portable.


Примечание (Note)

You probably want to use the lseek(2) wrapper function instead.


Смотри также (See also)

lseek(2), open(2), lseek64(3)