fseeko

FSEEKO(3)                   Linux Programmer's Manual                  FSEEKO(3)



NAME
       fseeko, ftello - seek to or report file position

SYNOPSIS
       #include <stdio.h>

       int fseeko(FILE *stream, off_t offset, int whence);
       off_t ftello(FILE *stream);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       fseeko(), ftello():
           _FILE_OFFSET_BITS == 64 || _POSIX_C_SOURCE >= 200112L

DESCRIPTION
       The fseeko() and ftello() functions are identical to fseek(3) and
       ftell(3) (see fseek(3)), respectively, except that the offset argument of
       fseeko() and the return value of ftello() is of type off_t instead of
       long.

       On some architectures, both off_t and long are 32-bit types, but defining
       _FILE_OFFSET_BITS with the value 64 (before including any header files)
       will turn off_t into a 64-bit type.

RETURN VALUE
       On successful completion, fseeko() returns 0, while ftello() returns the
       current offset.  Otherwise, -1 is returned and errno is set to indicate
       the error.

ERRORS
       See the ERRORS in fseek(3).

VERSIONS
       These functions are available under glibc since version 2.1.

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

       ┌──────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                     Attribute     Value   │
       ├──────────────────────────────────────────────┼───────────────┼─────────┤
       │fseeko(), ftello()                            │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, SUSv2.

NOTES
       The declarations of these functions can also be obtained by defining the
       obsolete _LARGEFILE_SOURCE feature test macro.

SEE ALSO
       fseek(3)

COLOPHON
       This page is part of release 5.11 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



                                   2021-03-22                          FSEEKO(3)