gd_validate3

Usage

Overview

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:
.TP 8 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.
.TP 8 GD_E_BAD_DIRFILE The supplied dirfile was invalid.
.TP 8 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.
.TP 8 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.