xenial (3) gd_nframes.3.gz

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
       Standards  (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
       returns zero and sets the dirfile error to a non-zero error value.  Possible error values are:

       GD_E_ALLOC
               The library was unable to allocate memory.

       GD_E_BAD_DIRFILE
               The supplied dirfile was invalid.

       GD_E_IO An attempt to determine the (unencoded) size of the data 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
               determined 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
               determined 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)