NAME¶
gd_nmvectors — report the number of vector fields in a dirfile
SYNOPSIS¶
#include <getdata.h>
unsigned
int gd_nmvectors(DIRFILE *dirfile);
DESCRIPTION¶
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).
RETURN VALUE¶
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:
- GD_E_BAD_CODE
- The supplied parent field code was not found, or referred
to a metafield itself.
- GD_E_BAD_DIRFILE
- 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).
SEE ALSO¶
dirfile(5),
gd_open(3),
gd_error(3),
gd_error_string(3),
gd_mvector_list(3),
gd_nmfields(3),
gd_nvectors(3)