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off_t(3type) off_t(3type)

NAME

off_t, off64_t, loff_t - file sizes

LIBRARY

Standard C library (libc)

SYNOPSIS

#include <sys/types.h>
typedef /* ... */  off_t;
#define _LARGEFILE64_SOURCE
#include <sys/types.h>
typedef /* ... */  off64_t;
#define _GNU_SOURCE
#include <sys/types.h>
typedef /* ... */  loff_t;

DESCRIPTION

off_t is used for describing file sizes. It is a signed integer type.

off64_t is a 64-bit version of the type, used in glibc.

loff_t is a 64-bit version of the type, introduced by the Linux kernel.

STANDARDS

POSIX.1-2008.
GNU and some BSDs.
Linux.

VERSIONS

POSIX.1-2001.

<aio.h> and <stdio.h> define off_t since POSIX.1-2008.

NOTES

On some architectures, the width of off_t can be controlled with the feature test macro _FILE_OFFSET_BITS.

The following headers also provide off_t: <aio.h>, <fcntl.h>, <stdio.h>, <sys/mman.h>, <sys/stat.h>, and <unistd.h>.

SEE ALSO

copy_file_range(2), llseek(2), lseek(2), mmap(2), posix_fadvise(2), pread(2), readahead(2), sync_file_range(2), truncate(2), fseeko(3), lockf(3), lseek64(3), posix_fallocate(3), feature_test_macros(7)

2024-05-02 Linux man-pages 6.8