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.

VERSIONS

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

STANDARDS

       off_t: POSIX.1-2001 and later.
       off64_t: Present in glibc and some BSDs.
       loff_t: Linux-specific.

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)