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 counts the number of metadata entries satisfying the provided 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_INDIR_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_SARRAY_ENTRY, GD_SBIT_ENTRY, GD_SINDIR_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, SARRAY, STRING).

GD_VECTOR_ENTRIES

Count only numeric-valued vector field types (all field types except SINDIR and 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).

This function has a subset of the functionality of the gd_match_entries(3) function (q.v.).

Special Cases

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RETURN VALUE

Upon successful completion, these functions return an unsigned in indicating the number of entries in the database satisfying the supplied criteria.

On error, these functions return zero and store a negative-valued error code in the DIRFILE object which may be retrieved by a subsequent call to gd_error(3). Possible error codes 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.

A descriptive error string for the error may be obtained by calling gd_error_string(3).

HISTORY

The get_nfields() function appeared in GetData-0.3.0.

The get_nfields_by_type(), get_nmfields(), get_nmfields_by_type(), get_nmvectors(), and get_nvectors() functions appeared in GetData-0.4.0.

In GetData-0.7.0, these functions were renamed to gd_nfields(), gd_nfields_by_type(), gd_nmfields(), gd_nmfields_by_type(), gd_nmvectors(), and gd_nvectors().

The gd_nentries() function appeared in GetData-0.8.0.

SEE ALSO

dirfile(5), gd_open(3), gd_entry_list(3), gd_error(3), gd_error_string(3), gd_hidden(3), gd_match_entries(3)

Last updated on 25 December 2016 for GetData Version 0.10.0.