gd_validate(3)							      GETDATA							    gd_validate(3)

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 represen-
       tation 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, whether the representation suffix (if any)  is  valid,  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 -1 and sets the dirfile error to a non-zero error value.  Possible
       error values 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_REPR
	       The representation suffix specified in field_code was not recognised.

       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.

       GD_E_RECURSE_LEVEL
	       Too many levels of recursion were encountered while trying to resolve field_code.  This usually indicates a circular dependency	in
	       field specification in the dirfile.

       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).

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.

SEE ALSO

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

Version 0.7.0							  3 November 2010						    gd_validate(3)