xenial (3) gd_frameoffset.3.gz

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  the frame offset of the specified fragment.  On
       error, it returns -1 and sets the dirfile error to a non-zero error value.  Possible error values are:

       GD_E_BAD_DIRFILE
               The supplied dirfile was invalid.

       GD_E_BAD_INDEX
               The supplied index was out of range.

       The dirfile error may be retrieved by calling gd_error(3).  A descriptive error string for the last error
       encountered can be obtained from a call to gd_error_string(3).

SEE ALSO

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