dell@amelia.nas.nasa.gov (Thomas E. Dell) (08/24/89)
- Question about Passing Structures and Pointer Initialization -
This is actually an interesting problem. I have a structure "OPTIONS"
defined as a structure consisting of integers, char *, and longs.
It is for a configuration file, but the application is not
too important. I pass a number of these structures to a routine
to set various items depending on context, as
setitem (line, Deflist);
as I read through the file. Outlined, the routine looks
something like :
setitem (string, Forum)
char *string; OPTIONS *List;
{
char *option, *arg;
[ set "option" to point to name of configuration item ]
[ set "arg" to point to its argument, or to "" if no argument ]
if (!stricmp (option, "alias")) /* string arg */
List->alias = strdup (arg);
else if (!stricmp (option, "group")) /* integer arg */
List->group = atoi (arg);
......
}
etc.. YUCK (There are over 30 available options).
My question is I have been unable to create a "configuration array"
to associate the string labels "alias", "group", etc. to elements of
the structure. Something like:
#ifdef UNDEFINED
{ "alias", CHAR, List->alias },
{ "group", INT, List->group },
#endif
Though, elsewhere in this program I have a similar setup where I can
{ "alias", CHAR, NULL, xAlias },
{ "group", INT, &xGroup, NULL },
^ Ints ^ Char *'s
for a different configuration, wherein it is possible to initialize
the configuration structure to tangible locations. (Yuck, but not as bad
as the YUCK above). This program must be "Extremely_Portable" and as such
I cannot use Unions, as one of machines does not support them.
Can someone who has done something like this before let me know a
better way? I hate putting YUCKs in the program.
-- Tom
dell@ames-nas.arpa
-----
(additional background if needed)
Structure format. OPTIONS is a linked list structure, hence
the funny definition. What is necessary is something like TABLE that
I can initialize. I don't mind using really strange things as long
as they are fairly portable.
typedef struct OPT typedef struct
{ {
char *alias; char *label;
int group; int type;
..etc... int *number;
} char *string;
OPTIONS; }
TABLE;