NAME

       gd_validate — check a Dirfile field code for validity

SYNOPSIS

       #include <getdata.h>

       int gd_validate(DIRFILE *dirfile, const char *field_code);

DESCRIPTION

       The  gd_validate()  function queries a dirfile(5) database specified by dirfile and checks
       whether field_code, which may contain a representation suffix, specifies a valid field.

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

       This  function  checks whether the field and its input fields (if any) are found, and also
       that all non-literal parameters specify valid scalar fields.

RETURN VALUE

       If all checks pass, gd_validate() returns zero.  On error, it  returns  a  negative-valued
       error code.  Possible error codes are:

       GD_E_BAD_CODE
               The  field  specified  by field_code or one of the fields it uses as input was not
               found in the database.

       GD_E_BAD_DIRFILE
               The supplied dirfile was invalid.

       GD_E_BAD_SCALAR
               A non-literal scalar used in the definition of the field or one of its inputs  was
               not found, or was not a CONST or CARRAY field.

       GD_E_DIMENSION
               A scalar field was found where a vector field was expected.

       The  error  code  is  also  stored  in  the DIRFILE object and may be retrieved after this
       function returns by calling gd_error(3).  A descriptive error string for the error may  be
       obtained by calling gd_error_string(3).

NOTES

       It  is  not necessary to call this function before passing a field code to another GetData
       function: all functions which accept field codes perform these checks themselves.

HISTORY

       The dirfile_validate(3) function appared in GetData-0.6.0.

       In GetData-0.7.0, this function was renamed to gd_validate(3).

       In GetData-0.10.0, the error return from this function changed  from  -1  to  a  negative-
       valued error code.

SEE ALSO

       gd_error(3), gd_error_string(3), gd_getdata(3), gd_open(3), dirfile(5)