lseek64(3)

lseek643

Reposition 64-bit read/write file offset

Usage

#define _LARGEFILE64_SOURCE     /* See feature_test_macros(7) */
#include <sys/types.h>
#include <unistd.h>

[[deprecated]] off64_t lseek64(int fd, off64_t offset, int whence);

Library

Standard C library (libc, -lc)

Overview

This function is equivalent to lseek(2) if one compiles with

#define _FILE_OFFSET_BITS 64

Use lseek(2) instead.

Attributes

For an explanation of the terms used in this section, see attributes(7).

InterfaceAttributeValue
lseek64()Thread safetyMT-Safe

Releases

11 releases since Debian 4.0 (Etch); the text changed 10 times.

  1. 4.0
  2. 5.0
  3. 6.0
  4. 7
  5. 8
  6. 9
  7. 10
  8. 11
  9. 12
  10. 13
  11. Arch

History

glibc 2.1.

lseek64() is one of the functions that was specified in the Large File Summit (LFS) specification that was completed in 1996. The purpose of the specification was to provide transitional support that allowed applications on 32-bit systems to access files whose size exceeds that which can be represented with a 32-bit off_t type.

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.