gd_nmvectors(3) report the number of vector fields in a dirfile


#include <getdata.h>
unsigned int gd_nmvectors(DIRFILE *dirfile);


The gd_nmvectors() function queries a dirfile(5) database specified by dirfile and returns the number of vector metafields defined in the database (i.e. fields of types BIT, LINCOM, LINTERP, MULTIPLY, PHASE, and RAW)for the supplied parent field.

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


Upon successful completion, gd_nmvectors() returns the number of vector metafields in the dirfile for the given parent. On error, it returns zero and sets the dirfile error to a non-zero error value. Possible error values are:
The supplied parent field code was not found, or referred to a metafield itself.
The supplied dirfile was invalid.

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).