NAME

       gd_nframes — report the size of a dirfile

SYNOPSIS

       #include <getdata.h>

       off_t gd_nframes(DIRFILE *dirfile);

DESCRIPTION

       The  gd_nframes()  function  queries a dirfile(5) database specified by dirfile and returns the number of
       frames in the database.  Since different fields may have differing number of frames,  the  Dirfile  Stan‐
       dards  (see  dirfile(5))  dictate that the number of frames in the database is defined to be equal to the
       number of frames in the reference field defined by the /REFERENCE directive (see  dirfile-format(5))  or,
       if no such reference field is defined, by the first raw field specified in the format specification.

       If no vector fields are defined in the database, gd_nframes() returns zero and succeeds.

       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_nframes() returns the number of frames in the dirfile.  On error, it re‐
       turns zero 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_RAW_IO
               An attempt to stat(2) the file associated with the reference field failed.

       GD_E_UNKNOWN_ENCODING
               The size of the decoded data file associated with the reference field could not be not be  deter‐
               mined because its encoding was not understood.

       GD_E_UNSUPPORTED
               The  size of the decoded data file associated with the reference field could not be not be deter‐
               mined because its encoding was not supported.

       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

       dirfile(5), dirfile-encoding(5), gd_open(3), gd_bof(3), gd_eof(3), gd_error(3), gd_error_string(3)

Version 0.7.0                                     22 July 2010                                     gd_nframes(3)