NAME

       gd_field_list — retrieve a list of fields in a dirfile

SYNOPSIS

       #include <getdata.h>

       const char **gd_field_list(DIRFILE *dirfile);

DESCRIPTION

       The  gd_field_list()  function  queries  a  dirfile(5)  database  specified by dirfile and
       returns a read-only list of names of the all fields defined  in  the  database.   Notably,
       this list does not include /META subfields.

       The  dirfile argument must point to a valid DIRFILE object previously created by a call to
       gd_open(3).

       The array returned will be de-allocated by a call to gd_close(3) and  should  not  be  de-
       allocated  by the caller.  The list returned should not be assumed to be in any particular
       order.  The array is terminated by a NULL pointer.  The number of strings in the array can
       be obtained from a call to gd_nfields(3).

       The  caller  may  not  modify any strings in the array, or the array itself.  Doing so may
       cause database  corruption.   The  pointer  returned  is  guaranteed  to  be  valid  until
       gd_field_list()  is  called  again  on  the same DIRFILE object, or until the array is de-
       allocated by a call to gd_close(3).

RETURN VALUE

       Upon successful completion, gd_field_list() returns a  pointer  to  an  array  of  strings
       containing  the  names  of  all  the  fields defined in the dirfile database.  On error it
       returns NULL and sets the dirfile error to a non-zero error value.  Possible error  values
       are:

       GD_E_ALLOC
               The library was unable to allocate memory.

       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_cbopen(3),  gd_error(3),   gd_error_string(3),   gd_field_list_by_type(3),
       gd_mfield_list(3), gd_nfields(3), gd_vector_list(3)