/*      GETARGS.C       Command line argument processor for C programs
 *
 *         (C) Copyright 1985, Allen I. Holub.  All rights reserved.
 *        This program may be copied for personal, non-profit use only.
 *
 * 4/15/86      Added usage arguemnt to getargs()
 * 3/10/87      DWS changed all "variable" references to "varptr" for T16
 */

#include <stdio.h>
#include "getargs.h"

/*----------------------------------------------------------------------*/
extern  int     stoi     ( char**       );
typedef int     (*PFI)();

/*----------------------------------------------------------------------*/

static char     *setarg( argp, linep )
ARG             *argp;
char            *linep;
{
        /*      Set an argument. argp points at the argument table entry
         *      corresponding to *linep. Return linep, updated to point
         *      past the argument being set.
         */

        ++linep;

        switch( argp->type )
        {
        case INTVAR:
                *argp->varptr = stoi( &linep );
                break;

        case BOOLEAN:
                *argp->varptr = 1;
                break;

        case CHARVAR:
                *argp->varptr = *linep++ ;
                break;

        case STRING:
                *(char **)argp->varptr = linep ;
                linep = "";
                break;

        case PROC:
                (* (PFI)(argp->varptr) )( linep );
                linep = "";
                break;

        default:
                fprintf(stderr,"INTERNAL ERROR: BAD ARGUMENT TYPE\n");
                break;
        }

        return( linep );
}

/*----------------------------------------------------------------------*/

static ARG      *findarg( c, tabp, tabsize )
int             c, tabsize;
ARG             *tabp;
{
        /*      Return pointer to argument table entry corresponding
         *      to c (or 0 if c isn't in table).
         */

        for(; --tabsize >= 0 ; tabp++ )
                if( tabp->arg == c )
                        return tabp;

        return 0;
}

static pr_usage( tabp, tabsize )
ARG     *tabp;
int     tabsize;
{
        /*      Print the argtab in the form:
         *              -<arg> <errmsg>     (value is <*varptr>)
         */

        for(; --tabsize >= 0 ;  tabp++ )
        {
                switch( tabp->type )
                {
                case INTVAR:
                        fprintf(stderr, "-%c<num> %-40s (value is ",
                                                tabp->arg, tabp->errmsg);
                        fprintf(stderr, "%-5d)\n", *(tabp->varptr) );
                        break;

                case BOOLEAN:
                        fprintf(stderr,"-%c      %-40s (value is ",
                                                tabp->arg, tabp->errmsg);
                        fprintf(stderr, "%-5s)\n", *(tabp->varptr)
                                                 ? "TRUE": "FALSE");
                        break;

                case CHARVAR:
                        fprintf(stderr, "-%c<c>   %-40s (value is ",
                                                tabp->arg, tabp->errmsg);
                        fprintf(stderr, "%-5c <%3x>x)\n", *(tabp->varptr), *(tabp->varptr) );
                        break;

                case STRING:
                        fprintf(stderr, "-%c<str> %-40s (value is ",
                                                tabp->arg, tabp->errmsg);
                        fprintf(stderr, "<%s>)\n",
                                                *(char **)tabp->varptr);
                        break;

                case PROC:
                        fprintf(stderr, "-%c<str> %-40s\n",
                                                tabp->arg, tabp->errmsg);
                        break;
                }
        }
exit(1);
}

#define ERRMSG  "Illegal argument <%c>.   Legal arguments are:\n\n"

int getargs( argc, argv, tabp, tabsize, usage )
int     argc, tabsize ;
char    **argv ;
ARG     *tabp  ;
int     (*usage)();
{
        /* Process command line arguments. Stripping all command line
         * switches out of argv. Return a new argc. If an error is found
         * exit(1) is called (getargs won't return) and a usage message
         * is printed showing all arguments in the table.
         */

        register int    nargc       ;
        register char   **nargv, *p ;
        register ARG    *argp       ;

        nargc = 1 ;
        for(nargv = ++argv ; --argc > 0 ; argv++ )
        {
                if( **argv != SWITCHAR )
                {
                        *nargv++ = *argv ;
                        nargc++;
                }
                else
                {
                        p = (*argv) + 1 ;

                        while( *p )
                        {
                                if(argp = findarg(*p, tabp, tabsize))
                                        p = setarg( argp, p );
                                else
                                {
                                        fprintf(stderr, ERRMSG, *p );
                                        pr_usage( tabp, tabsize );
                                        (*usage)();
                                }
                        }
                }
        }
        return nargc ;
}