Manpages - fseeko.3

fseeko, ftello - seek to or report file position

  #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

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.

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

See the ERRORS in *fseek*(3).

These functions are available under glibc since version 2.1.

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

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

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

*fseek*(3)

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