1/*****************************************************************************
2* getopt.c - competent and free getopt library.
3* $Header: /cvsroot/freegetopt/freegetopt/getopt.c,v 1.2 2003/10/26 03:10:20 vindaci Exp $
4 *
5* Copyright (c)2002-2003 Mark K. Kim
6* All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12*   * Redistributions of source code must retain the above copyright
13 *     notice, this list of conditions and the following disclaimer.
14 *
15*   * Redistributions in binary form must reproduce the above copyright
16*     notice, this list of conditions and the following disclaimer in
17*     the documentation and/or other materials provided with the
18*     distribution.
19*
20*   * Neither the original author of this software nor the names of its
21*     contributors may be used to endorse or promote products derived
22*     from this software without specific prior written permission.
23*
24* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
27* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
28* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
29* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
30* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
31* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
32* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
33* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
34* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
35* DAMAGE.
36*/
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include "getopt.h"
41
42
43static const char* ID = "$Id: getopt.c,v 1.2 2003/10/26 03:10:20 vindaci Exp $";
44
45
46char* optarg = NULL;
47int optind = 0;
48int opterr = 1;
49int optopt = '?';
50
51
52static char** prev_argv = NULL;        /* Keep a copy of argv and argc to */
53static int prev_argc = 0;              /*    tell if getopt params change */
54static int argv_index = 0;             /* Option we're checking */
55static int argv_index2 = 0;            /* Option argument we're checking */
56static int opt_offset = 0;             /* Index into compounded "-option" */
57static int dashdash = 0;               /* True if "--" option reached */
58static int nonopt = 0;                 /* How many nonopts we've found */
59
60static void increment_index()
61{
62	/* Move onto the next option */
63	if(argv_index < argv_index2)
64	{
65		while(prev_argv[++argv_index] && prev_argv[argv_index][0] != '-'
66				&& argv_index < argv_index2+1);
67	}
68	else argv_index++;
69	opt_offset = 1;
70}
71
72
73/*
74* Permutes argv[] so that the argument currently being processed is moved
75* to the end.
76*/
77static int permute_argv_once()
78{
79	/* Movability check */
80	if(argv_index + nonopt >= prev_argc) return 1;
81	/* Move the current option to the end, bring the others to front */
82	else
83	{
84		char* tmp = prev_argv[argv_index];
85
86		/* Move the data */
87		memmove(&prev_argv[argv_index], &prev_argv[argv_index+1],
88				sizeof(char**) * (prev_argc - argv_index - 1));
89		prev_argv[prev_argc - 1] = tmp;
90
91		nonopt++;
92		return 0;
93	}
94}
95
96
97int getopt(int argc, char* const argv[], const char* optstr)
98{
99	int c = 0;
100
101	/* If we have new argv, reinitialize */
102	if(prev_argv != argv || prev_argc != argc)
103	{
104		/* Initialize variables */
105		prev_argv = argv;
106		prev_argc = argc;
107		argv_index = 1;
108		argv_index2 = 1;
109		opt_offset = 1;
110		dashdash = 0;
111		nonopt = 0;
112	}
113
114	/* Jump point in case we want to ignore the current argv_index */
115	getopt_top:
116
117	/* Misc. initializations */
118	optarg = NULL;
119
120	/* Dash-dash check */
121	if(argv[argv_index] && !strcmp(argv[argv_index], "--"))
122	{
123		dashdash = 1;
124		increment_index();
125	}
126
127	/* If we're at the end of argv, that's it. */
128	if(argv[argv_index] == NULL)
129	{
130		c = -1;
131	}
132	/* Are we looking at a string? Single dash is also a string */
133	else if(dashdash || argv[argv_index][0] != '-' || !strcmp(argv[argv_index], "-"))
134	{
135		/* If we want a string... */
136		if(optstr[0] == '-')
137		{
138			c = 1;
139			optarg = argv[argv_index];
140			increment_index();
141		}
142		/* If we really don't want it (we're in POSIX mode), we're done */
143		else if(optstr[0] == '+' || getenv("POSIXLY_CORRECT"))
144		{
145			c = -1;
146
147			/* Everything else is a non-opt argument */
148			nonopt = argc - argv_index;
149		}
150		/* If we mildly don't want it, then move it back */
151		else
152		{
153			if(!permute_argv_once()) goto getopt_top;
154			else c = -1;
155		}
156	}
157	/* Otherwise we're looking at an option */
158	else
159	{
160		char* opt_ptr = NULL;
161
162		/* Grab the option */
163		c = argv[argv_index][opt_offset++];
164
165		/* Is the option in the optstr? */
166		if(optstr[0] == '-') opt_ptr = strchr(optstr+1, c);
167		else opt_ptr = strchr(optstr, c);
168		/* Invalid argument */
169		if(!opt_ptr)
170		{
171			if(opterr)
172			{
173				fprintf(stderr, "%s: invalid option -- %c\n", argv[0], c);
174			}
175
176			optopt = c;
177			c = '?';
178
179			/* Move onto the next option */
180			increment_index();
181		}
182		/* Option takes argument */
183		else if(opt_ptr[1] == ':')
184		{
185			/* ie, -oARGUMENT, -xxxoARGUMENT, etc. */
186			if(argv[argv_index][opt_offset] != '\0')
187			{
188				optarg = &argv[argv_index][opt_offset];
189				increment_index();
190			}
191			/* ie, -o ARGUMENT (only if it's a required argument) */
192			else if(opt_ptr[2] != ':')
193			{
194				/* One of those "you're not expected to understand this" moment */
195				if(argv_index2 < argv_index) argv_index2 = argv_index;
196				while(argv[++argv_index2] && argv[argv_index2][0] == '-');
197				optarg = argv[argv_index2];
198
199				/* Don't cross into the non-option argument list */
200				if(argv_index2 + nonopt >= prev_argc) optarg = NULL;
201
202				/* Move onto the next option */
203				increment_index();
204			}
205			else
206			{
207				/* Move onto the next option */
208				increment_index();
209			}
210
211			/* In case we got no argument for an option with required argument */
212			if(optarg == NULL && opt_ptr[2] != ':')
213			{
214				optopt = c;
215				c = '?';
216
217				if(opterr)
218				{
219					fprintf(stderr,"%s: option requires an argument -- %c\n",
220							argv[0], optopt);
221				}
222			}
223		}
224		/* Option does not take argument */
225		else
226		{
227			/* Next argv_index */
228			if(argv[argv_index][opt_offset] == '\0')
229			{
230				increment_index();
231			}
232		}
233	}
234
235	/* Calculate optind */
236	if(c == -1)
237	{
238		optind = argc - nonopt;
239	}
240	else
241	{
242		optind = argv_index;
243	}
244
245	return c;
246}
247
248
249/* vim:ts=3
250*/
251