.\" gd_nfields_by_type.3.  The gd_nfields_by_type man page.
.\"
.\" Copyright (C) 2008, 2010 D. V. Wiebe
.\"
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.TH gd_nfields_by_type 3 "3 November 2010" "Version 0.7.0" "GETDATA"
.SH NAME
gd_nfields_by_type \(em report the number of fields of a given type in a dirfile
.SH SYNOPSIS
.B #include <getdata.h>
.HP
.nh
.ad l
.BI "unsigned int gd_nfields_by_type(DIRFILE *" dirfile ", gd_entype_t " type );
.hy
.ad n
.SH DESCRIPTION
The
.BR gd_nfields_by_type ()
function queries a dirfile(5) database specified by
.I dirfile
and returns the number of fields of type
.I type
defined in the database.  Notably, this count
does not include /META fields.

The 
.I dirfile
argument must point to a valid DIRFILE object previously created by a call to
.BR gd_open (3).
The
.I type
argument should be one of the following symbols indicating the type of field to
count:
.IP
.nh
.ad l
.BR GD_BIT_ENTRY ", " GD_CARRAY_ENTRY ", " GD_CONST_ENTRY ", " GD_DIVIDE_ENTRY ,
.BR GD_INDEX_ENTRY ", " GD_LINCOM_ENTRY ", " GD_LINTERP_ENTRY ,
.BR GD_MULTIPLY_ENTRY ", " GD_PHASE_ENTRY ", " GD_POLYNOM_ENTRY ,
.BR GD_RAW_ENTRY ", " GD_RECIP_ENTRY ", " GD_SBIT_ENTRY ", " GD_STRING_ENTRY .
.ad n
.hy

.SH RETURN VALUE
Upon successful completion,
.BR gd_nfields_by_type ()
returns the number of defined fields in the dirfile.  On error, it
returns zero and sets the dirfile error
to a non-zero error value.  Possible error values are:
.TP 8
.B GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
.PP
The dirfile error may be retrieved by calling
.BR gd_error (3).
A descriptive error string for the last error encountered can be obtained from
a call to
.BR gd_error_string (3).
.SH SEE ALSO
.BR dirfile (5),
.BR gd_open (3),
.BR gd_error (3),
.BR gd_error_string (3),
.BR gd_field_list_by_type (3),
.BR gd_nfields (3),
.BR gd_nmfields_by_type (3)