xref: /dragonfly/contrib/flex/src/scanopt.c (revision 388e4ddaf1c230f115961bdb4bad6a8d3e017c93)
1 /* flex - tool to generate fast lexical analyzers */
2 
3 /*  Copyright (c) 1990 The Regents of the University of California. */
4 /*  All rights reserved. */
5 
6 /*  This code is derived from software contributed to Berkeley by */
7 /*  Vern Paxson. */
8 
9 /*  The United States Government has rights in this work pursuant */
10 /*  to contract no. DE-AC03-76SF00098 between the United States */
11 /*  Department of Energy and the University of California. */
12 
13 /*  This file is part of flex. */
14 
15 /*  Redistribution and use in source and binary forms, with or without */
16 /*  modification, are permitted provided that the following conditions */
17 /*  are met: */
18 
19 /*  1. Redistributions of source code must retain the above copyright */
20 /*     notice, this list of conditions and the following disclaimer. */
21 /*  2. Redistributions in binary form must reproduce the above copyright */
22 /*     notice, this list of conditions and the following disclaimer in the */
23 /*     documentation and/or other materials provided with the distribution. */
24 
25 /*  Neither the name of the University nor the names of its contributors */
26 /*  may be used to endorse or promote products derived from this software */
27 /*  without specific prior written permission. */
28 
29 /*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
30 /*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
31 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
32 /*  PURPOSE. */
33 
34 #include "flexdef.h"
35 #include "scanopt.h"
36 
37 
38 /* Internal structures */
39 
40 #define ARG_NONE 0x01
41 #define ARG_REQ  0x02
42 #define ARG_OPT  0x04
43 #define IS_LONG  0x08
44 
45 struct _aux {
46           int     flags;                /* The above hex flags. */
47           int     namelen;    /* Length of the actual option word, e.g., "--file[=foo]" is 4 */
48           int     printlen;   /* Length of entire string, e.g., "--file[=foo]" is 12 */
49 };
50 
51 
52 struct _scanopt_t {
53           const optspec_t *options;     /* List of options. */
54           struct _aux *aux;   /* Auxiliary data about options. */
55           int     optc;                 /* Number of options. */
56           int     argc;                 /* Number of args. */
57           char  **argv;                 /* Array of strings. */
58           int     index;                /* Used as: argv[index][subscript]. */
59           int     subscript;
60           char    no_err_msg; /* If true, do not print errors. */
61           char    has_long;
62           char    has_short;
63 };
64 
65 /* Accessor functions. These WOULD be one-liners, but portability calls. */
66 static const char *NAME(struct _scanopt_t *, int);
67 static int PRINTLEN(struct _scanopt_t *, int);
68 static int RVAL(struct _scanopt_t *, int);
69 static int FLAGS(struct _scanopt_t *, int);
70 static const char *DESC(struct _scanopt_t *, int);
71 static int scanopt_err(struct _scanopt_t *, int, int);
72 static int matchlongopt(char *, char **, int *, char **, int *);
73 static int find_opt(struct _scanopt_t *, int, char *, int, int *, int *opt_offset);
74 
NAME(struct _scanopt_t * s,int i)75 static const char *NAME (struct _scanopt_t *s, int i)
76 {
77           return s->options[i].opt_fmt +
78                     ((s->aux[i].flags & IS_LONG) ? 2 : 1);
79 }
80 
PRINTLEN(struct _scanopt_t * s,int i)81 static int PRINTLEN (struct _scanopt_t *s, int i)
82 {
83           return s->aux[i].printlen;
84 }
85 
RVAL(struct _scanopt_t * s,int i)86 static int RVAL (struct _scanopt_t *s, int i)
87 {
88           return s->options[i].r_val;
89 }
90 
FLAGS(struct _scanopt_t * s,int i)91 static int FLAGS (struct _scanopt_t *s, int i)
92 {
93           return s->aux[i].flags;
94 }
95 
DESC(struct _scanopt_t * s,int i)96 static const char *DESC (struct _scanopt_t *s, int i)
97 {
98           return s->options[i].desc ? s->options[i].desc : "";
99 }
100 
101 #ifndef NO_SCANOPT_USAGE
102 static int get_cols (void);
103 
get_cols(void)104 static int get_cols (void)
105 {
106           char   *env;
107           int     cols = 80;  /* default */
108 
109 #ifdef HAVE_NCURSES_H
110           initscr ();
111           endwin ();
112           if (COLS > 0)
113                     return COLS;
114 #endif
115 
116           if ((env = getenv ("COLUMNS")) != NULL)
117                     cols = atoi (env);
118 
119           return cols;
120 }
121 #endif
122 
123 /* Macro to check for NULL before assigning a value. */
124 #define SAFE_ASSIGN(ptr,val) \
125     do{                      \
126         if((ptr)!=NULL)      \
127             *(ptr) = val;    \
128     }while(0)
129 
130 /* Macro to assure we reset subscript whenever we adjust s->index.*/
131 #define INC_INDEX(s,n)     \
132     do{                    \
133        (s)->index += (n);  \
134        (s)->subscript= 0;  \
135     }while(0)
136 
scanopt_init(const optspec_t * options,int argc,char ** argv,int flags)137 scanopt_t *scanopt_init (const optspec_t *options, int argc, char **argv, int flags)
138 {
139           int     i;
140           struct _scanopt_t *s;
141           s = malloc(sizeof (struct _scanopt_t));
142 
143           s->options = options;
144           s->optc = 0;
145           s->argc = argc;
146           s->argv = (char **) argv;
147           s->index = 1;
148           s->subscript = 0;
149           s->no_err_msg = (flags & SCANOPT_NO_ERR_MSG);
150           s->has_long = 0;
151           s->has_short = 0;
152 
153           /* Determine option count. (Find entry with all zeros). */
154           s->optc = 0;
155           while (options[s->optc].opt_fmt
156                  || options[s->optc].r_val || options[s->optc].desc)
157                     s->optc++;
158 
159           /* Build auxiliary data */
160           s->aux = malloc((size_t) s->optc * sizeof (struct _aux));
161 
162           for (i = 0; i < s->optc; i++) {
163                     const unsigned char *p, *pname;
164                     const struct optspec_t *opt;
165                     struct _aux *aux;
166 
167                     opt = s->options + i;
168                     aux = s->aux + i;
169 
170                     aux->flags = ARG_NONE;
171 
172                     if (opt->opt_fmt[0] == '-' && opt->opt_fmt[1] == '-') {
173                               aux->flags |= IS_LONG;
174                               pname = (const unsigned char *)(opt->opt_fmt + 2);
175                               s->has_long = 1;
176                     }
177                     else {
178                               pname = (const unsigned char *)(opt->opt_fmt + 1);
179                               s->has_short = 1;
180                     }
181                     aux->printlen = (int) strlen (opt->opt_fmt);
182 
183                     aux->namelen = 0;
184                     for (p = pname + 1; *p; p++) {
185                               /* detect required arg */
186                               if (*p == '=' || isspace ((unsigned char)*p)
187                                   || !(aux->flags & IS_LONG)) {
188                                         if (aux->namelen == 0)
189                                                   aux->namelen = (int) (p - pname);
190                                         aux->flags |= ARG_REQ;
191                                         aux->flags &= ~ARG_NONE;
192                               }
193                               /* detect optional arg. This overrides required arg. */
194                               if (*p == '[') {
195                                         if (aux->namelen == 0)
196                                                   aux->namelen = (int) (p - pname);
197                                         aux->flags &= ~(ARG_REQ | ARG_NONE);
198                                         aux->flags |= ARG_OPT;
199                                         break;
200                               }
201                     }
202                     if (aux->namelen == 0)
203                               aux->namelen = (int) (p - pname);
204           }
205           return (scanopt_t *) s;
206 }
207 
208 #ifndef NO_SCANOPT_USAGE
209 /* these structs are for scanopt_usage(). */
210 struct usg_elem {
211           int     idx;
212           struct usg_elem *next;
213           struct usg_elem *alias;
214 };
215 typedef struct usg_elem usg_elem;
216 
217 
218 /* Prints a usage message based on contents of optlist.
219  * Parameters:
220  *   scanner  - The scanner, already initialized with scanopt_init().
221  *   fp       - The file stream to write to.
222  *   usage    - Text to be prepended to option list.
223  * Return:  Always returns 0 (zero).
224  * The output looks something like this:
225 
226 [indent][option, alias1, alias2...][indent][description line1
227                                             description line2...]
228  */
scanopt_usage(scanopt_t * scanner,FILE * fp,const char * usage)229 int     scanopt_usage (scanopt_t *scanner, FILE *fp, const char *usage)
230 {
231           struct _scanopt_t *s;
232           int     i, columns, indent = 2;
233           usg_elem *byr_val = NULL;     /* option indices sorted by r_val */
234           usg_elem *store;    /* array of preallocated elements. */
235           int     store_idx = 0;
236           usg_elem *ue;
237           int     maxlen[2];
238           int     desccol = 0;
239           int     print_run = 0;
240 
241           maxlen[0] = 0;
242           maxlen[1] = 0;
243 
244           s = (struct _scanopt_t *) scanner;
245 
246           if (usage) {
247                     fprintf (fp, "%s\n", usage);
248           }
249           else {
250                     /* Find the basename of argv[0] */
251                     const char *p;
252 
253                     p = s->argv[0] + strlen (s->argv[0]);
254                     while (p != s->argv[0] && *p != '/')
255                               --p;
256                     if (*p == '/')
257                               p++;
258 
259                     fprintf (fp, _("Usage: %s [OPTIONS]...\n"), p);
260           }
261           fprintf (fp, "\n");
262 
263           /* Sort by r_val and string. Yes, this is O(n*n), but n is small. */
264           store = malloc((size_t) s->optc * sizeof (usg_elem));
265           for (i = 0; i < s->optc; i++) {
266 
267                     /* grab the next preallocate node. */
268                     ue = store + store_idx++;
269                     ue->idx = i;
270                     ue->next = ue->alias = NULL;
271 
272                     /* insert into list. */
273                     if (!byr_val)
274                               byr_val = ue;
275                     else {
276                               int     found_alias = 0;
277                               usg_elem **ue_curr, **ptr_if_no_alias = NULL;
278 
279                               ue_curr = &byr_val;
280                               while (*ue_curr) {
281                                         if (RVAL (s, (*ue_curr)->idx) ==
282                                             RVAL (s, ue->idx)) {
283                                                   /* push onto the alias list. */
284                                                   ue_curr = &((*ue_curr)->alias);
285                                                   found_alias = 1;
286                                                   break;
287                                         }
288                                         if (!ptr_if_no_alias
289                                             &&
290                                             strcasecmp (NAME (s, (*ue_curr)->idx),
291                                                             NAME (s, ue->idx)) > 0) {
292                                                   ptr_if_no_alias = ue_curr;
293                                         }
294                                         ue_curr = &((*ue_curr)->next);
295                               }
296                               if (!found_alias && ptr_if_no_alias)
297                                         ue_curr = ptr_if_no_alias;
298                               ue->next = *ue_curr;
299                               *ue_curr = ue;
300                     }
301           }
302 
303 #if 0
304           if (1) {
305                     printf ("ORIGINAL:\n");
306                     for (i = 0; i < s->optc; i++)
307                               printf ("%2d: %s\n", i, NAME (s, i));
308                     printf ("SORTED:\n");
309                     ue = byr_val;
310                     while (ue) {
311                               usg_elem *ue2;
312 
313                               printf ("%2d: %s\n", ue->idx, NAME (s, ue->idx));
314                               for (ue2 = ue->alias; ue2; ue2 = ue2->next)
315                                         printf ("  +---> %2d: %s\n", ue2->idx,
316                                                   NAME (s, ue2->idx));
317                               ue = ue->next;
318                     }
319           }
320 #endif
321 
322           /* Now build each row of output. */
323 
324           /* first pass calculate how much room we need. */
325           for (ue = byr_val; ue; ue = ue->next) {
326                     usg_elem *ap;
327                     int     len = 0;
328                     int     nshort = 0, nlong = 0;
329 
330 
331 #define CALC_LEN(i) do {\
332           if(FLAGS(s,i) & IS_LONG) \
333               len +=  (nlong++||nshort) ? 2+PRINTLEN(s,i) : PRINTLEN(s,i);\
334           else\
335               len +=  (nshort++||nlong)? 2+PRINTLEN(s,i) : PRINTLEN(s,i);\
336         }while(0)
337 
338                     if (!(FLAGS (s, ue->idx) & IS_LONG))
339                               CALC_LEN (ue->idx);
340 
341                     /* do short aliases first. */
342                     for (ap = ue->alias; ap; ap = ap->next) {
343                               if (FLAGS (s, ap->idx) & IS_LONG)
344                                         continue;
345                               CALC_LEN (ap->idx);
346                     }
347 
348                     if (FLAGS (s, ue->idx) & IS_LONG)
349                               CALC_LEN (ue->idx);
350 
351                     /* repeat the above loop, this time for long aliases. */
352                     for (ap = ue->alias; ap; ap = ap->next) {
353                               if (!(FLAGS (s, ap->idx) & IS_LONG))
354                                         continue;
355                               CALC_LEN (ap->idx);
356                     }
357 
358                     if (len > maxlen[0])
359                               maxlen[0] = len;
360 
361                     /* It's much easier to calculate length for description column! */
362                     len = (int) strlen (DESC (s, ue->idx));
363                     if (len > maxlen[1])
364                               maxlen[1] = len;
365           }
366 
367           /* Determine how much room we have, and how much we will allocate to each col.
368            * Do not address pathological cases. Output will just be ugly. */
369           columns = get_cols () - 1;
370           if (maxlen[0] + maxlen[1] + indent * 2 > columns) {
371                     /* col 0 gets whatever it wants. we'll wrap the desc col. */
372                     maxlen[1] = columns - (maxlen[0] + indent * 2);
373                     if (maxlen[1] < 14) /* 14 is arbitrary lower limit on desc width. */
374                               maxlen[1] = INT_MAX;
375           }
376           desccol = maxlen[0] + indent * 2;
377 
378 #define PRINT_SPACES(fp,n)\
379     do{\
380         int _n;\
381         _n=(n);\
382         while(_n-- > 0)\
383             fputc(' ',(fp));\
384     }while(0)
385 
386 
387           /* Second pass (same as above loop), this time we print. */
388           /* Sloppy hack: We iterate twice. The first time we print short and long options.
389              The second time we print those lines that have ONLY long options. */
390           while (print_run++ < 2) {
391                     for (ue = byr_val; ue; ue = ue->next) {
392                               usg_elem *ap;
393                               int     nwords = 0, nchars = 0, has_short = 0;
394 
395 /* TODO: get has_short schtick to work */
396                               has_short = !(FLAGS (s, ue->idx) & IS_LONG);
397                               for (ap = ue->alias; ap; ap = ap->next) {
398                                         if (!(FLAGS (s, ap->idx) & IS_LONG)) {
399                                                   has_short = 1;
400                                                   break;
401                                         }
402                               }
403                               if ((print_run == 1 && !has_short) ||
404                                   (print_run == 2 && has_short))
405                                         continue;
406 
407                               PRINT_SPACES (fp, indent);
408                               nchars += indent;
409 
410 /* Print, adding a ", " between aliases. */
411 #define PRINT_IT(i) do{\
412                   if(nwords++)\
413                       nchars+=fprintf(fp,", ");\
414                   nchars+=fprintf(fp,"%s",s->options[i].opt_fmt);\
415             }while(0)
416 
417                               if (!(FLAGS (s, ue->idx) & IS_LONG))
418                                         PRINT_IT (ue->idx);
419 
420                               /* print short aliases first. */
421                               for (ap = ue->alias; ap; ap = ap->next) {
422                                         if (!(FLAGS (s, ap->idx) & IS_LONG))
423                                                   PRINT_IT (ap->idx);
424                               }
425 
426 
427                               if (FLAGS (s, ue->idx) & IS_LONG)
428                                         PRINT_IT (ue->idx);
429 
430                               /* repeat the above loop, this time for long aliases. */
431                               for (ap = ue->alias; ap; ap = ap->next) {
432                                         if (FLAGS (s, ap->idx) & IS_LONG)
433                                                   PRINT_IT (ap->idx);
434                               }
435 
436                               /* pad to desccol */
437                               PRINT_SPACES (fp, desccol - nchars);
438 
439                               /* Print description, wrapped to maxlen[1] columns. */
440                               if (1) {
441                                         const char *pstart;
442 
443                                         pstart = DESC (s, ue->idx);
444                                         while (1) {
445                                                   int     n = 0;
446                                                   const char *lastws = NULL, *p;
447 
448                                                   p = pstart;
449 
450                                                   while (*p && n < maxlen[1]
451                                                          && *p != '\n') {
452                                                             if (isspace ((unsigned char)(*p))
453                                                                 || *p == '-') lastws =
454                                                                                 p;
455                                                             n++;
456                                                             p++;
457                                                   }
458 
459                                                   if (!*p) {          /* hit end of desc. done. */
460                                                             fprintf (fp, "%s\n",
461                                                                        pstart);
462                                                             break;
463                                                   }
464                                                   else if (*p == '\n') {        /* print everything up to here then wrap. */
465                                                             fprintf (fp, "%.*s\n", n,
466                                                                        pstart);
467                                                             PRINT_SPACES (fp, desccol);
468                                                             pstart = p + 1;
469                                                             continue;
470                                                   }
471                                                   else {    /* we hit the edge of the screen. wrap at space if possible. */
472                                                             if (lastws) {
473                                                                       fprintf (fp,
474                                                                                  "%.*s\n",
475                                                                                  (int)(lastws - pstart),
476                                                                                  pstart);
477                                                                       pstart =
478                                                                                 lastws + 1;
479                                                             }
480                                                             else {
481                                                                       fprintf (fp,
482                                                                                  "%.*s\n",
483                                                                                  n,
484                                                                                  pstart);
485                                                                       pstart = p + 1;
486                                                             }
487                                                             PRINT_SPACES (fp, desccol);
488                                                             continue;
489                                                   }
490                                         }
491                               }
492                     }
493           }                             /* end while */
494           free (store);
495           return 0;
496 }
497 #endif /* no scanopt_usage */
498 
499 
scanopt_err(struct _scanopt_t * s,int is_short,int err)500 static int scanopt_err (struct _scanopt_t *s, int is_short, int err)
501 {
502           const char *optname = "";
503           char    optchar[2];
504 
505           if (!s->no_err_msg) {
506 
507                     if (s->index > 0 && s->index < s->argc) {
508                               if (is_short) {
509                                         optchar[0] =
510                                                   s->argv[s->index][s->subscript];
511                                         optchar[1] = '\0';
512                                         optname = optchar;
513                               }
514                               else {
515                                         optname = s->argv[s->index];
516                               }
517                     }
518 
519                     fprintf (stderr, "%s: ", s->argv[0]);
520                     switch (err) {
521                     case SCANOPT_ERR_ARG_NOT_ALLOWED:
522                               fprintf (stderr,
523                                          _
524                                          ("option `%s' doesn't allow an argument\n"),
525                                          optname);
526                               break;
527                     case SCANOPT_ERR_ARG_NOT_FOUND:
528                               fprintf (stderr,
529                                          _("option `%s' requires an argument\n"),
530                                          optname);
531                               break;
532                     case SCANOPT_ERR_OPT_AMBIGUOUS:
533                               fprintf (stderr, _("option `%s' is ambiguous\n"),
534                                          optname);
535                               break;
536                     case SCANOPT_ERR_OPT_UNRECOGNIZED:
537                               fprintf (stderr, _("Unrecognized option `%s'\n"),
538                                          optname);
539                               break;
540                     default:
541                               fprintf (stderr, _("Unknown error=(%d)\n"), err);
542                               break;
543                     }
544           }
545           return err;
546 }
547 
548 
549 /* Internal. Match str against the regex  ^--([^=]+)(=(.*))?
550  * return 1 if *looks* like a long option.
551  * 'str' is the only input argument, the rest of the arguments are output only.
552  * optname will point to str + 2
553  *
554  */
matchlongopt(char * str,char ** optname,int * optlen,char ** arg,int * arglen)555 static int matchlongopt (char *str, char **optname, int *optlen, char **arg, int *arglen)
556 {
557           char   *p;
558 
559           *optname = *arg = NULL;
560           *optlen = *arglen = 0;
561 
562           /* Match regex /--./   */
563           p = str;
564           if (p[0] != '-' || p[1] != '-' || !p[2])
565                     return 0;
566 
567           p += 2;
568           *optname = p;
569 
570           /* find the end of optname */
571           while (*p && *p != '=')
572                     ++p;
573 
574           *optlen = (int) (p - *optname);
575 
576           if (!*p)
577                     /* an option with no '=...' part. */
578                     return 1;
579 
580 
581           /* We saw an '=' char. The rest of p is the arg. */
582           p++;
583           *arg = p;
584           while (*p)
585                     ++p;
586           *arglen = (int) (p - *arg);
587 
588           return 1;
589 }
590 
591 
592 /* Internal. Look up long or short option by name.
593  * Long options must match a non-ambiguous prefix, or exact match.
594  * Short options must be exact.
595  * Return boolean true if found and no error.
596  * Error stored in err_code or zero if no error. */
find_opt(struct _scanopt_t * s,int lookup_long,char * optstart,int len,int * err_code,int * opt_offset)597 static int find_opt (struct _scanopt_t *s, int lookup_long, char *optstart, int
598           len, int *err_code, int *opt_offset)
599 {
600           int     nmatch = 0, lastr_val = 0, i;
601 
602           *err_code = 0;
603           *opt_offset = -1;
604 
605           if (!optstart)
606                     return 0;
607 
608           for (i = 0; i < s->optc; i++) {
609                     const char   *optname;
610 
611                     optname = s->options[i].opt_fmt + (lookup_long ? 2 : 1);
612 
613                     if (lookup_long && (s->aux[i].flags & IS_LONG)) {
614                               if (len > s->aux[i].namelen)
615                                         continue;
616 
617                               if (strncmp (optname, optstart, (size_t) len) == 0) {
618                                         nmatch++;
619                                         *opt_offset = i;
620 
621                                         /* exact match overrides all. */
622                                         if (len == s->aux[i].namelen) {
623                                                   nmatch = 1;
624                                                   break;
625                                         }
626 
627                                         /* ambiguity is ok between aliases. */
628                                         if (lastr_val
629                                             && lastr_val ==
630                                             s->options[i].r_val) nmatch--;
631                                         lastr_val = s->options[i].r_val;
632                               }
633                     }
634                     else if (!lookup_long && !(s->aux[i].flags & IS_LONG)) {
635                               if (optname[0] == optstart[0]) {
636                                         nmatch++;
637                                         *opt_offset = i;
638                               }
639                     }
640           }
641 
642           if (nmatch == 0) {
643                     *err_code = SCANOPT_ERR_OPT_UNRECOGNIZED;
644                     *opt_offset = -1;
645           }
646           else if (nmatch > 1) {
647                     *err_code = SCANOPT_ERR_OPT_AMBIGUOUS;
648                     *opt_offset = -1;
649           }
650 
651           return *err_code ? 0 : 1;
652 }
653 
654 
scanopt(scanopt_t * svoid,char ** arg,int * optindex)655 int     scanopt (scanopt_t *svoid, char **arg, int *optindex)
656 {
657           char   *optname = NULL, *optarg = NULL, *pstart;
658           int     namelen = 0, arglen = 0;
659           int     errcode = 0, has_next;
660           const optspec_t *optp;
661           struct _scanopt_t *s;
662           struct _aux *auxp;
663           int     is_short;
664           int     opt_offset = -1;
665 
666           s = (struct _scanopt_t *) svoid;
667 
668           /* Normalize return-parameters. */
669           SAFE_ASSIGN (arg, NULL);
670           SAFE_ASSIGN (optindex, s->index);
671 
672           if (s->index >= s->argc)
673                     return 0;
674 
675           /* pstart always points to the start of our current scan. */
676           pstart = s->argv[s->index] + s->subscript;
677           if (!pstart)
678                     return 0;
679 
680           if (s->subscript == 0) {
681 
682                     /* test for exact match of "--" */
683                     if (pstart[0] == '-' && pstart[1] == '-' && !pstart[2]) {
684                               SAFE_ASSIGN (optindex, s->index + 1);
685                               INC_INDEX (s, 1);
686                               return 0;
687                     }
688 
689                     /* Match an opt. */
690                     if (matchlongopt
691                         (pstart, &optname, &namelen, &optarg, &arglen)) {
692 
693                               /* it LOOKS like an opt, but is it one?! */
694                               if (!find_opt
695                                   (s, 1, optname, namelen, &errcode,
696                                    &opt_offset)) {
697                                         scanopt_err (s, 0, errcode);
698                                         return errcode;
699                               }
700                               /* We handle this below. */
701                               is_short = 0;
702 
703                               /* Check for short opt.  */
704                     }
705                     else if (pstart[0] == '-' && pstart[1]) {
706                               /* Pass through to below. */
707                               is_short = 1;
708                               s->subscript++;
709                               pstart++;
710                     }
711 
712                     else {
713                               /* It's not an option. We're done. */
714                               return 0;
715                     }
716           }
717 
718           /* We have to re-check the subscript status because it
719            * may have changed above. */
720 
721           if (s->subscript != 0) {
722 
723                     /* we are somewhere in a run of short opts,
724                      * e.g., at the 'z' in `tar -xzf` */
725 
726                     optname = pstart;
727                     namelen = 1;
728                     is_short = 1;
729 
730                     if (!find_opt
731                         (s, 0, pstart, namelen, &errcode, &opt_offset)) {
732                               return scanopt_err (s, 1, errcode);
733                     }
734 
735                     optarg = pstart + 1;
736                     if (!*optarg) {
737                               optarg = NULL;
738                               arglen = 0;
739                     }
740                     else
741                               arglen = (int) strlen (optarg);
742           }
743 
744           /* At this point, we have a long or short option matched at opt_offset into
745            * the s->options array (and corresponding aux array).
746            * A trailing argument is in {optarg,arglen}, if any.
747            */
748 
749           /* Look ahead in argv[] to see if there is something
750            * that we can use as an argument (if needed). */
751           has_next = s->index + 1 < s->argc
752                     && strcmp ("--", s->argv[s->index + 1]) != 0;
753 
754           optp = s->options + opt_offset;
755           auxp = s->aux + opt_offset;
756 
757           /* case: no args allowed */
758           if (auxp->flags & ARG_NONE) {
759                     if (optarg && !is_short) {
760                               scanopt_err (s, is_short, errcode = SCANOPT_ERR_ARG_NOT_ALLOWED);
761                               INC_INDEX (s, 1);
762                               return errcode;
763                     }
764                     else if (!optarg)
765                               INC_INDEX (s, 1);
766                     else
767                               s->subscript++;
768                     return optp->r_val;
769           }
770 
771           /* case: required */
772           if (auxp->flags & ARG_REQ) {
773                     if (!optarg && !has_next)
774                               return scanopt_err (s, is_short, SCANOPT_ERR_ARG_NOT_FOUND);
775 
776                     if (!optarg) {
777                               /* Let the next argv element become the argument. */
778                               SAFE_ASSIGN (arg, s->argv[s->index + 1]);
779                               INC_INDEX (s, 2);
780                     }
781                     else {
782                               SAFE_ASSIGN (arg, (char *) optarg);
783                               INC_INDEX (s, 1);
784                     }
785                     return optp->r_val;
786           }
787 
788           /* case: optional */
789           if (auxp->flags & ARG_OPT) {
790                     SAFE_ASSIGN (arg, optarg);
791                     INC_INDEX (s, 1);
792                     return optp->r_val;
793           }
794 
795 
796           /* Should not reach here. */
797           return 0;
798 }
799 
800 
scanopt_destroy(scanopt_t * svoid)801 int     scanopt_destroy (scanopt_t *svoid)
802 {
803           struct _scanopt_t *s;
804 
805           s = (struct _scanopt_t *) svoid;
806           if (s != NULL) {
807                     free(s->aux);
808                     free(s);
809           }
810           return 0;
811 }
812 
813 
814 /* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */
815