gd_nentries(3)

NAME
gd_nentries, gd_nfields, gd_nfields_by_type gd_nmfields, gd_nmfields_by_type, gd_nmvectors, gd_nvectors — count field entries in a dirfile

SYNOPSIS
#include <getdata.h>

unsigned int gd_nentries(DIRFILE *dirfile, const char *parent, unsigned int type, unsigned int flags);

unsigned int gd_nfields(DIRFILE *dirfile);

unsigned int gd_nfields_by_type(DIRFILE *dirfile, gd_entype_t type);

unsigned int gd_nmfields(DIRFILE *dirfile, const char *parent);

unsigned int gd_nmfields_by_type(DIRFILE *dirfile, const char *parent, gd_entype_t type);

unsigned int gd_nmvectors(DIRFILE *dirfile, const char *parent);

unsigned int gd_nvectors(DIRFILE *dirfile);

DESCRIPTION
The gd_nentries() function queries a dirfile(5) database specified by dirfile and returns a count of metadata entries satisfying the supplied criteria. If parent is non-NULL, metafields under the field specified by parent are considered; otherwise, top-level fields are considered, and metafields ignored.

The type argument should be one of the following symbols indicating an explicit entry type to count:

    GD_BIT_ENTRY, GD_CARRAY_ENTRY, GD_CONST_ENTRY, GD_DIVIDE_ENTRY, GD_INDEX_ENTRY, GD_LINCOM_ENTRY, GD_LINTERP_ENTRY, GD_MPLEX_ENTRY, GD_MULTIPLY_ENTRY, GD_PHASE_ENTRY, GD_POLYNOM_ENTRY, GD_RAW_ENTRY, GD_RECIP_ENTRY, GD_SBIT_ENTRY, GD_STRING_ENTRY, GD_WINDOW_ENTRY.

(GD_INDEX_ENTRY is a special field type for the implicit INDEX field) or else one of the following special symbols:

GD_ALL_ENTRIES (= 0)
    Count entries of all types.

GD_ALIAS_ENTRIES
    Count only aliases. This is the only way to get a count including aliases which do not point to valid field codes.

GD_SCALAR_ENTRIES
    Count only scalar field types (CONST, CARRAY, STRING).

GD_VECTOR_ENTRIES
    Count only vector field types (all field types except the scalar field types listed above).

The flags argument should be zero or more of the following flags, bitwise or'd together:

GD_ENTRIES_HIDDEN
    Include hidden entries (see gd_hidden(3)) in the count: normally hidden entries are skipped;

GD_ENTRIES_NOALIAS
    Exclude aliases from the count: normally aliases are considered the same as their target (that is: a field with n aliases, plus its canonical name, will be counted n+1 times).

  Special Cases
The call
    gd_nfields(dirfile);

is equivalent to
    gd_nentries(dirfile, NULL, GD_ALL_ENTRIES, 0);

The call
    gd_nfields_by_type(dirfile, type);

is equivalent to
    gd_nentries(dirfile, NULL, type, 0);

The call
    gd_nmfields(dirfile, parent);

is equivalent to
    gd_nentries(dirfile, parent, GD_ALL_ENTRIES, 0);

The call
    gd_nmfields_by_type(dirfile, parent, type);

is equivalent to
    gd_nentries(dirfile, parent, type, 0);

The call
    gd_nmvectors(dirfile, parent);

is equivalent to
    gd_nentries(dirfile, parent, GD_VECTOR_ENTRIES, 0);

The call
    gd_nvectors(dirfile);

is equivalent to
    gd_nentries(dirfile, NULL, GD_VECTOR_ENTRIES, 0);

RETURN VALUE
Upon successful completion, these functions return the number of entries in the database satisfying the supplied criteria. On error, they return 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.

GD_E_BAD_ENTRY
    The type parameter supplied was not one of the symbols listed above.

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_entry_list(3), gd_error(3), gd_error_string(3), gd_hidden(3)