PURPOSE

Fvopt, Fvopt32 - change flag options of a mapping entry

SYNOPSIS

#include <stdio.h>
#include "fml.h"
int
Fvopt(char *cname, int option, char *view)
#include "fml32.h"
int
Fvopt32(char *cname, int option, char *view)

DESCRIPTION

Fvopt() allows users to specify buffer-to-structure mapping options at runtime. cname is a pointer to the name of an element in a view description, view. option specifies the desired setting for the mapping option. Valid options and their meanings are:

F_FTOS

one-way mapping from fielded buffer to structure, flag S in the view description

F_STOF

one-way mapping from structure to fielded buffer, flag F in the view description

F_OFF

no mapping between the fielded buffer and the structure, flag N in the view description

F_BOTH

two-way mapping between the fielded buffer and the structure, flag S,F in the view description

Fvopt32 is used for views defined with viewc32 or VIEW32 typed buffers for larger views with more fields.

RETURN VALUES

This function returns -1 on error and sets Ferror to indicate the error condition.

ERRORS

Under the following conditions, Fvopt() fails and sets Ferror to:

[FEINVAL]

"invalid argument to function"
One of the arguments to the function invoked was invalid (for example, specifying a NULL cname or view parameter or specifying an invalid option).

 

[FBADVIEW]

"cannot find or get view"
The view was not found in the files specified by VIEWDIR and VIEWFILES.

 

[FNOCNAME]

"cname not found"
The C structure field name is not found in the view description.

SEE ALSO

Fintro(3fml),
viewfile(5)