1 /* argmatch.c -- find a match for a string in an array
2
3 Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2012 Free Software
4 Foundation, Inc.
5
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 /* Written by David MacKenzie <djm@ai.mit.edu>
20 Modified by Akim Demaille <demaille@inf.enst.fr> */
21
22 #include <config.h>
23
24 /* Specification. */
25 #include "argmatch.h"
26
27 #include <stdbool.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 #include "gettext.h"
33 #define _(msgid) gettext (msgid)
34
35 #include "error.h"
36 #include "quotearg.h"
37 #include "quote.h"
38
39 #if USE_UNLOCKED_IO
40 # include "unlocked-io.h"
41 #endif
42
43 /* When reporting an invalid argument, show nonprinting characters
44 by using the quoting style ARGMATCH_QUOTING_STYLE. Do not use
45 literal_quoting_style. */
46 #ifndef ARGMATCH_QUOTING_STYLE
47 # define ARGMATCH_QUOTING_STYLE locale_quoting_style
48 #endif
49
50 /* Non failing version of argmatch call this function after failing. */
51 #ifndef ARGMATCH_DIE
52 # include "exitfail.h"
53 # define ARGMATCH_DIE exit (exit_failure)
54 #endif
55
56 #ifdef ARGMATCH_DIE_DECL
57 ARGMATCH_DIE_DECL;
58 #endif
59
60 static void
__argmatch_die(void)61 __argmatch_die (void)
62 {
63 ARGMATCH_DIE;
64 }
65
66 /* Used by XARGMATCH and XARGCASEMATCH. See description in argmatch.h.
67 Default to __argmatch_die, but allow caller to change this at run-time. */
68 argmatch_exit_fn argmatch_die = __argmatch_die;
69
70
71 /* If ARG is an unambiguous match for an element of the
72 NULL-terminated array ARGLIST, return the index in ARGLIST
73 of the matched element, else -1 if it does not match any element
74 or -2 if it is ambiguous (is a prefix of more than one element).
75
76 If VALLIST is none null, use it to resolve ambiguities limited to
77 synonyms, i.e., for
78 "yes", "yop" -> 0
79 "no", "nope" -> 1
80 "y" is a valid argument, for 0, and "n" for 1. */
81
82 ptrdiff_t
argmatch(const char * arg,const char * const * arglist,const char * vallist,size_t valsize)83 argmatch (const char *arg, const char *const *arglist,
84 const char *vallist, size_t valsize)
85 {
86 size_t i; /* Temporary index in ARGLIST. */
87 size_t arglen; /* Length of ARG. */
88 ptrdiff_t matchind = -1; /* Index of first nonexact match. */
89 bool ambiguous = false; /* If true, multiple nonexact match(es). */
90
91 arglen = strlen (arg);
92
93 /* Test all elements for either exact match or abbreviated matches. */
94 for (i = 0; arglist[i]; i++)
95 {
96 if (!strncmp (arglist[i], arg, arglen))
97 {
98 if (strlen (arglist[i]) == arglen)
99 /* Exact match found. */
100 return i;
101 else if (matchind == -1)
102 /* First nonexact match found. */
103 matchind = i;
104 else
105 {
106 /* Second nonexact match found. */
107 if (vallist == NULL
108 || memcmp (vallist + valsize * matchind,
109 vallist + valsize * i, valsize))
110 {
111 /* There is a real ambiguity, or we could not
112 disambiguate. */
113 ambiguous = true;
114 }
115 }
116 }
117 }
118 if (ambiguous)
119 return -2;
120 else
121 return matchind;
122 }
123
124 /* Error reporting for argmatch.
125 CONTEXT is a description of the type of entity that was being matched.
126 VALUE is the invalid value that was given.
127 PROBLEM is the return value from argmatch. */
128
129 void
argmatch_invalid(const char * context,const char * value,ptrdiff_t problem)130 argmatch_invalid (const char *context, const char *value, ptrdiff_t problem)
131 {
132 char const *format = (problem == -1
133 ? _("invalid argument %s for %s")
134 : _("ambiguous argument %s for %s"));
135
136 error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value),
137 quote_n (1, context));
138 }
139
140 /* List the valid arguments for argmatch.
141 ARGLIST is the same as in argmatch.
142 VALLIST is a pointer to an array of values.
143 VALSIZE is the size of the elements of VALLIST */
144 void
argmatch_valid(const char * const * arglist,const char * vallist,size_t valsize)145 argmatch_valid (const char *const *arglist,
146 const char *vallist, size_t valsize)
147 {
148 size_t i;
149 const char *last_val = NULL;
150
151 /* We try to put synonyms on the same line. The assumption is that
152 synonyms follow each other */
153 fputs (_("Valid arguments are:"), stderr);
154 for (i = 0; arglist[i]; i++)
155 if ((i == 0)
156 || memcmp (last_val, vallist + valsize * i, valsize))
157 {
158 fprintf (stderr, "\n - %s", quote (arglist[i]));
159 last_val = vallist + valsize * i;
160 }
161 else
162 {
163 fprintf (stderr, ", %s", quote (arglist[i]));
164 }
165 putc ('\n', stderr);
166 }
167
168 /* Never failing versions of the previous functions.
169
170 CONTEXT is the context for which argmatch is called (e.g.,
171 "--version-control", or "$VERSION_CONTROL" etc.). Upon failure,
172 calls the (supposed never to return) function EXIT_FN. */
173
174 ptrdiff_t
__xargmatch_internal(const char * context,const char * arg,const char * const * arglist,const char * vallist,size_t valsize,argmatch_exit_fn exit_fn)175 __xargmatch_internal (const char *context,
176 const char *arg, const char *const *arglist,
177 const char *vallist, size_t valsize,
178 argmatch_exit_fn exit_fn)
179 {
180 ptrdiff_t res = argmatch (arg, arglist, vallist, valsize);
181 if (res >= 0)
182 /* Success. */
183 return res;
184
185 /* We failed. Explain why. */
186 argmatch_invalid (context, arg, res);
187 argmatch_valid (arglist, vallist, valsize);
188 (*exit_fn) ();
189
190 return -1; /* To please the compilers. */
191 }
192
193 /* Look for VALUE in VALLIST, an array of objects of size VALSIZE and
194 return the first corresponding argument in ARGLIST */
195 const char *
argmatch_to_argument(const char * value,const char * const * arglist,const char * vallist,size_t valsize)196 argmatch_to_argument (const char *value,
197 const char *const *arglist,
198 const char *vallist, size_t valsize)
199 {
200 size_t i;
201
202 for (i = 0; arglist[i]; i++)
203 if (!memcmp (value, vallist + valsize * i, valsize))
204 return arglist[i];
205 return NULL;
206 }
207
208 #ifdef TEST
209 /*
210 * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu>
211 */
212 char *program_name;
213
214 /* When to make backup files. */
215 enum backup_type
216 {
217 /* Never make backups. */
218 no_backups,
219
220 /* Make simple backups of every file. */
221 simple_backups,
222
223 /* Make numbered backups of files that already have numbered backups,
224 and simple backups of the others. */
225 numbered_existing_backups,
226
227 /* Make numbered backups of every file. */
228 numbered_backups
229 };
230
231 /* Two tables describing arguments (keys) and their corresponding
232 values */
233 static const char *const backup_args[] =
234 {
235 "no", "none", "off",
236 "simple", "never",
237 "existing", "nil",
238 "numbered", "t",
239 0
240 };
241
242 static const enum backup_type backup_vals[] =
243 {
244 no_backups, no_backups, no_backups,
245 simple_backups, simple_backups,
246 numbered_existing_backups, numbered_existing_backups,
247 numbered_backups, numbered_backups
248 };
249
250 int
main(int argc,const char * const * argv)251 main (int argc, const char *const *argv)
252 {
253 const char *cp;
254 enum backup_type backup_type = no_backups;
255
256 program_name = (char *) argv[0];
257
258 if (argc > 2)
259 {
260 fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", program_name);
261 exit (1);
262 }
263
264 if ((cp = getenv ("VERSION_CONTROL")))
265 backup_type = XARGMATCH ("$VERSION_CONTROL", cp,
266 backup_args, backup_vals);
267
268 if (argc == 2)
269 backup_type = XARGMATCH (program_name, argv[1],
270 backup_args, backup_vals);
271
272 printf ("The version control is '%s'\n",
273 ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals));
274
275 return 0;
276 }
277 #endif
278