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
       (defining the obsolete _LARGEFILE_SOURCE macro also works)


   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

   Interface           Attribute      Value   
   fseeko(), ftello()  Thread safety  MT-Safe 


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




   This  page  is  part of release 4.09 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

                              2016-03-15                         FSEEKO(3)


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