1 /* argmatch.c -- find a match for a string in an array
2
3 Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2017 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 #include "getprogname.h"
39
40 #if USE_UNLOCKED_IO
41 # include "unlocked-io.h"
42 #endif
43
44 /* When reporting an invalid argument, show nonprinting characters
45 by using the quoting style ARGMATCH_QUOTING_STYLE. Do not use
46 literal_quoting_style. */
47 #ifndef ARGMATCH_QUOTING_STYLE
48 # define ARGMATCH_QUOTING_STYLE locale_quoting_style
49 #endif
50
51 /* Non failing version of argmatch call this function after failing. */
52 #ifndef ARGMATCH_DIE
53 # include "exitfail.h"
54 # define ARGMATCH_DIE exit (exit_failure)
55 #endif
56
57 #ifdef ARGMATCH_DIE_DECL
58 ARGMATCH_DIE_DECL;
59 #endif
60
61 static void
__argmatch_die(void)62 __argmatch_die (void)
63 {
64 ARGMATCH_DIE;
65 }
66
67 /* Used by XARGMATCH and XARGCASEMATCH. See description in argmatch.h.
68 Default to __argmatch_die, but allow caller to change this at run-time. */
69 argmatch_exit_fn argmatch_die = __argmatch_die;
70
71
72 /* If ARG is an unambiguous match for an element of the
73 NULL-terminated array ARGLIST, return the index in ARGLIST
74 of the matched element, else -1 if it does not match any element
75 or -2 if it is ambiguous (is a prefix of more than one element).
76
77 If VALLIST is none null, use it to resolve ambiguities limited to
78 synonyms, i.e., for
79 "yes", "yop" -> 0
80 "no", "nope" -> 1
81 "y" is a valid argument, for 0, and "n" for 1. */
82
83 ptrdiff_t
argmatch(const char * arg,const char * const * arglist,const char * vallist,size_t valsize)84 argmatch (const char *arg, const char *const *arglist,
85 const char *vallist, size_t valsize)
86 {
87 size_t i; /* Temporary index in ARGLIST. */
88 size_t arglen; /* Length of ARG. */
89 ptrdiff_t matchind = -1; /* Index of first nonexact match. */
90 bool ambiguous = false; /* If true, multiple nonexact match(es). */
91
92 arglen = strlen (arg);
93
94 /* Test all elements for either exact match or abbreviated matches. */
95 for (i = 0; arglist[i]; i++)
96 {
97 if (!strncmp (arglist[i], arg, arglen))
98 {
99 if (strlen (arglist[i]) == arglen)
100 /* Exact match found. */
101 return i;
102 else if (matchind == -1)
103 /* First nonexact match found. */
104 matchind = i;
105 else
106 {
107 /* Second nonexact match found. */
108 if (vallist == NULL
109 || memcmp (vallist + valsize * matchind,
110 vallist + valsize * i, valsize))
111 {
112 /* There is a real ambiguity, or we could not
113 disambiguate. */
114 ambiguous = true;
115 }
116 }
117 }
118 }
119 if (ambiguous)
120 return -2;
121 else
122 return matchind;
123 }
124
125 /* Error reporting for argmatch.
126 CONTEXT is a description of the type of entity that was being matched.
127 VALUE is the invalid value that was given.
128 PROBLEM is the return value from argmatch. */
129
130 void
argmatch_invalid(const char * context,const char * value,ptrdiff_t problem)131 argmatch_invalid (const char *context, const char *value, ptrdiff_t problem)
132 {
133 char const *format = (problem == -1
134 ? _("invalid argument %s for %s")
135 : _("ambiguous argument %s for %s"));
136
137 error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value),
138 quote_n (1, context));
139 }
140
141 /* List the valid arguments for argmatch.
142 ARGLIST is the same as in argmatch.
143 VALLIST is a pointer to an array of values.
144 VALSIZE is the size of the elements of VALLIST */
145 void
argmatch_valid(const char * const * arglist,const char * vallist,size_t valsize)146 argmatch_valid (const char *const *arglist,
147 const char *vallist, size_t valsize)
148 {
149 size_t i;
150 const char *last_val = NULL;
151
152 /* We try to put synonyms on the same line. The assumption is that
153 synonyms follow each other */
154 fputs (_("Valid arguments are:"), stderr);
155 for (i = 0; arglist[i]; i++)
156 if ((i == 0)
157 || memcmp (last_val, vallist + valsize * i, valsize))
158 {
159 fprintf (stderr, "\n - %s", quote (arglist[i]));
160 last_val = vallist + valsize * i;
161 }
162 else
163 {
164 fprintf (stderr, ", %s", quote (arglist[i]));
165 }
166 putc ('\n', stderr);
167 }
168
169 /* Never failing versions of the previous functions.
170
171 CONTEXT is the context for which argmatch is called (e.g.,
172 "--version-control", or "$VERSION_CONTROL" etc.). Upon failure,
173 calls the (supposed never to return) function EXIT_FN. */
174
175 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)176 __xargmatch_internal (const char *context,
177 const char *arg, const char *const *arglist,
178 const char *vallist, size_t valsize,
179 argmatch_exit_fn exit_fn)
180 {
181 ptrdiff_t res = argmatch (arg, arglist, vallist, valsize);
182 if (res >= 0)
183 /* Success. */
184 return res;
185
186 /* We failed. Explain why. */
187 argmatch_invalid (context, arg, res);
188 argmatch_valid (arglist, vallist, valsize);
189 (*exit_fn) ();
190
191 return -1; /* To please the compilers. */
192 }
193
194 /* Look for VALUE in VALLIST, an array of objects of size VALSIZE and
195 return the first corresponding argument in ARGLIST */
196 const char *
argmatch_to_argument(const char * value,const char * const * arglist,const char * vallist,size_t valsize)197 argmatch_to_argument (const char *value,
198 const char *const *arglist,
199 const char *vallist, size_t valsize)
200 {
201 size_t i;
202
203 for (i = 0; arglist[i]; i++)
204 if (!memcmp (value, vallist + valsize * i, valsize))
205 return arglist[i];
206 return NULL;
207 }
208
209 #ifdef TEST
210 /*
211 * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu>
212 */
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 if (argc > 2)
257 {
258 fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", getprogname ());
259 exit (1);
260 }
261
262 if ((cp = getenv ("VERSION_CONTROL")))
263 backup_type = XARGMATCH ("$VERSION_CONTROL", cp,
264 backup_args, backup_vals);
265
266 if (argc == 2)
267 backup_type = XARGMATCH (getprogname (), argv[1],
268 backup_args, backup_vals);
269
270 printf ("The version control is '%s'\n",
271 ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals));
272
273 return 0;
274 }
275 #endif
276