NAME

       gd_frameoffset — report the starting frame of fields in a Dirfile

SYNOPSIS

       #include <getdata.h>

       off_t gd_frameoffset(DIRFILE *dirfile, int fragment_index);

DESCRIPTION

       The  gd_frameoffset()  function  queries a dirfile(5) database specified by dirfile and returns the frame
       offset (see dirfile-format(5)) for the fragment  indexed  by  fragment_index.   The  frame  offset  of  a
       fragment indicate the frame number of the first sample of data stored in binary files associated with RAW
       fields defined in the specified fragment.  The frame offset of a fragment containing  no  RAW  fields  is
       ignored.

       The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).

RETURN VALUE

       Upon  successful  completion, gd_frameoffset() returns a non-negative integer containing the frame offset
       of the specified fragment.  On error, it returns a negative-valued error code.  Possible error codes are:

       GD_E_BAD_DIRFILE
               The supplied dirfile was invalid.

       GD_E_BAD_INDEX
               The supplied index was out of range.

       The error code is also stored in the DIRFILE object and may be retrieved after this function  returns  by
       calling   gd_error(3).    A   descriptive  error  string  for  the  error  may  be  obtained  by  calling
       gd_error_string(3).

HISTORY

       The get_frameoffset() function appeared in GetData-0.5.0.

       In GetData-0.7.0, this function was renamed to gd_frameoffset().

       In GetData-0.10.0, the error return from this function changed from -1 to a negative-valued error code.

SEE ALSO

       gd_alter_frameoffset(3), gd_error(3), gd_error_string(3), gd_open(3), dirfile(5), dirfile-format(5)