NAME

       gd_vector_list — retrieve a list of vector fields in a dirfile

SYNOPSIS

       #include <getdata.h>

       const char **gd_vector_list(DIRFILE *dirfile);

DESCRIPTION

       The  gd_vector_list()  function  queries  a  dirfile(5)  database specified by dirfile and
       returns a read-only list of names of the all vector type fields defined  in  the  database
       (i.e.   fields  of  types  BIT,  LINCOM,  LINTERP,  MULTIPLY,  PHASE, POLYNOM, RAW, SBIT).
       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_nvectors(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_vector_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_vector_list()  returns  a pointer to an array of strings
       containing the names of all the vector 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_open(3),     gd_error(3),     gd_error_string(3),     gd_field_list(3),
       gd_mvector_list(3), gd_nvectors(3)