date and time created 93/04/30 13:30:02 by muller

[unix-history] / usr / src / usr.bin / pr / egetopt.c

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)egetopt.c   5.1 (Berkeley) %G%";
#endif /* not lint */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "extern.h"

/*
* egetopt:     get option letter from argument vector (an extended
*              version of getopt).
*
* Non standard additions to the ostr specs are:
* 1) '?': immediate value following arg is optional (no white space
*    between the arg and the value)
* 2) '#': +/- followed by a number (with an optional sign but
*    no white space between the arg and the number). The - may be
*    combined with other options, but the + cannot.
*/

int     eopterr = 1;            /* if error message should be printed */
int     eoptind = 1;            /* index into parent argv vector */
int     eoptopt;                /* character checked for validity */
char    *eoptarg;               /* argument associated with option */

#define BADCH   (int)'?'
#define EMSG    ""

#if __STDC__
int
egetopt(int nargc, char * const *nargv, const char *ostr)
#else
int
egetopt(nargc, nargv, ostr)
       int nargc;
       char **nargv;
       char *ostr;
#endif
{
       static char *place = EMSG;      /* option letter processing */
       register char *oli;             /* option letter list index */
       static int delim;               /* which option delimeter */
       register char *p;
       static char savec = '\0';

       if (savec != '\0') {
               *place = savec;
               savec = '\0';
       }

       if (!*place) {
               /*
                * update scanning pointer
                */
               if ((eoptind >= nargc) ||
                   ((*(place = nargv[eoptind]) != '-') && (*place != '+'))) {
                       place = EMSG;
                       return(EOF);
               }

               delim = (int)*place;
               if (place[1] && *++place == '-' && !place[1]) {
                       /*
                        * found "--"
                        */
                       ++eoptind;
                       place = EMSG;
                       return(EOF);
               }
       }

       /*
        * check option letter
        */
       if ((eoptopt = (int)*place++) == (int)':' || (eoptopt == (int)'?') ||
           !(oli = index(ostr, eoptopt))) {
               /*
                * if the user didn't specify '-' as an option,
                * assume it means EOF when by itself.
                */
               if ((eoptopt == (int)'-') && !*place)
                       return(EOF);
               if (index(ostr, '#') && (isdigit(eoptopt) ||
                   (((eoptopt == (int)'-') || (eoptopt == (int)'+')) &&
                     isdigit(*place)))) {
                       /*
                        * # option: +/- with a number is ok
                        */
                       for (p = place; *p != '\0'; ++p) {
                               if (!isdigit(*p))
                                       break;
                       }
                       eoptarg = place-1;

                       if (*p == '\0') {
                               place = EMSG;
                               ++eoptind;
                       } else {
                               place = p;
                               savec = *p;
                               *place = '\0';
                       }
                       return(delim);
               }

               if (!*place)
                       ++eoptind;
               if (eopterr) {
                       if (!(p = rindex(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr, "%s: illegal option -- %c\n",
                           p, eoptopt);
               }
               return(BADCH);
       }
       if (delim == (int)'+') {
               /*
                * '+' is only allowed with numbers
                */
               if (!*place)
                       ++eoptind;
               if (eopterr) {
                       if (!(p = rindex(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr,
                               "%s: illegal '+' delimiter with option -- %c\n",
                               p, eoptopt);
               }
               return(BADCH);
       }
       ++oli;
       if ((*oli != ':') && (*oli != '?')) {
               /*
                * don't need argument
                */
               eoptarg = NULL;
               if (!*place)
                       ++eoptind;
               return(eoptopt);
       }

       if (*place) {
               /*
                * no white space
                */
               eoptarg = place;
       } else if (*oli == '?') {
               /*
                * no arg, but NOT required
                */
               eoptarg = NULL;
       } else if (nargc <= ++eoptind) {
               /*
                * no arg, but IS required
                */
               place = EMSG;
               if (eopterr) {
                       if (!(p = rindex(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr,
                           "%s: option requires an argument -- %c\n", p,
                           eoptopt);
               }
               return(BADCH);
       } else {
               /*
                * arg has white space
                */
               eoptarg = nargv[eoptind];
       }
       place = EMSG;
       ++eoptind;
       return(eoptopt);
}