Provided by: libgetdata-doc_0.10.0-5build2_all bug

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
       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 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)