1 /* argmatch.c -- find a match for a string in an array
2
3 Copyright (C) 1990, 1998, 1999, 2001, 2002, 2003, 2004, 2005, 2006
4 Free Software 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 2, or (at your option)
9 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, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20 /* Written by David MacKenzie <djm@ai.mit.edu>
21 Modified by Akim Demaille <demaille@inf.enst.fr> */
22
23 #include <config.h>
24
25 /* Specification. */
26 #include "argmatch.h"
27
28 #include <stdbool.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32
33 #include "gettext.h"
34 #define _(msgid) gettext (msgid)
35
36 #include "error.h"
37 #include "exit.h"
38 #include "quotearg.h"
39 #include "quote.h"
40
41 #if USE_UNLOCKED_IO
42 # include "unlocked-io.h"
43 #endif
44
45 /* When reporting an invalid argument, show nonprinting characters
46 by using the quoting style ARGMATCH_QUOTING_STYLE. Do not use
47 literal_quoting_style. */
48 #ifndef ARGMATCH_QUOTING_STYLE
49 # define ARGMATCH_QUOTING_STYLE locale_quoting_style
50 #endif
51
52 /* Non failing version of argmatch call this function after failing. */
53 #ifndef ARGMATCH_DIE
54 # include "exitfail.h"
55 # define ARGMATCH_DIE exit (exit_failure)
56 #endif
57
58 #ifdef ARGMATCH_DIE_DECL
59 ARGMATCH_DIE_DECL;
60 #endif
61
62 static void
__argmatch_die(void)63 __argmatch_die (void)
64 {
65 ARGMATCH_DIE;
66 }
67
68 /* Used by XARGMATCH and XARGCASEMATCH. See description in argmatch.h.
69 Default to __argmatch_die, but allow caller to change this at run-time. */
70 argmatch_exit_fn argmatch_die = __argmatch_die;
71
72
73 /* If ARG is an unambiguous match for an element of the
74 NULL-terminated array ARGLIST, return the index in ARGLIST
75 of the matched element, else -1 if it does not match any element
76 or -2 if it is ambiguous (is a prefix of more than one element).
77
78 If VALLIST is none null, use it to resolve ambiguities limited to
79 synonyms, i.e., for
80 "yes", "yop" -> 0
81 "no", "nope" -> 1
82 "y" is a valid argument, for `0', and "n" for `1'. */
83
84 ptrdiff_t
argmatch(const char * arg,const char * const * arglist,const char * vallist,size_t valsize)85 argmatch (const char *arg, const char *const *arglist,
86 const char *vallist, size_t valsize)
87 {
88 size_t i; /* Temporary index in ARGLIST. */
89 size_t arglen; /* Length of ARG. */
90 ptrdiff_t matchind = -1; /* Index of first nonexact match. */
91 bool ambiguous = false; /* If true, multiple nonexact match(es). */
92
93 arglen = strlen (arg);
94
95 /* Test all elements for either exact match or abbreviated matches. */
96 for (i = 0; arglist[i]; i++)
97 {
98 if (!strncmp (arglist[i], arg, arglen))
99 {
100 if (strlen (arglist[i]) == arglen)
101 /* Exact match found. */
102 return i;
103 else if (matchind == -1)
104 /* First nonexact match found. */
105 matchind = i;
106 else
107 {
108 /* Second nonexact match found. */
109 if (vallist == NULL
110 || memcmp (vallist + valsize * matchind,
111 vallist + valsize * i, valsize))
112 {
113 /* There is a real ambiguity, or we could not
114 disambiguate. */
115 ambiguous = true;
116 }
117 }
118 }
119 }
120 if (ambiguous)
121 return -2;
122 else
123 return matchind;
124 }
125
126 /* Error reporting for argmatch.
127 CONTEXT is a description of the type of entity that was being matched.
128 VALUE is the invalid value that was given.
129 PROBLEM is the return value from argmatch. */
130
131 void
argmatch_invalid(const char * context,const char * value,ptrdiff_t problem)132 argmatch_invalid (const char *context, const char *value, ptrdiff_t problem)
133 {
134 char const *format = (problem == -1
135 ? _("invalid argument %s for %s")
136 : _("ambiguous argument %s for %s"));
137
138 error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value),
139 quote_n (1, context));
140 }
141
142 /* List the valid arguments for argmatch.
143 ARGLIST is the same as in argmatch.
144 VALLIST is a pointer to an array of values.
145 VALSIZE is the size of the elements of VALLIST */
146 void
argmatch_valid(const char * const * arglist,const char * vallist,size_t valsize)147 argmatch_valid (const char *const *arglist,
148 const char *vallist, size_t valsize)
149 {
150 size_t i;
151 const char *last_val = NULL;
152
153 /* We try to put synonyms on the same line. The assumption is that
154 synonyms follow each other */
155 fprintf (stderr, _("Valid arguments are:"));
156 for (i = 0; arglist[i]; i++)
157 if ((i == 0)
158 || memcmp (last_val, vallist + valsize * i, valsize))
159 {
160 fprintf (stderr, "\n - `%s'", arglist[i]);
161 last_val = vallist + valsize * i;
162 }
163 else
164 {
165 fprintf (stderr, ", `%s'", arglist[i]);
166 }
167 putc ('\n', stderr);
168 }
169
170 /* Never failing versions of the previous functions.
171
172 CONTEXT is the context for which argmatch is called (e.g.,
173 "--version-control", or "$VERSION_CONTROL" etc.). Upon failure,
174 calls the (supposed never to return) function EXIT_FN. */
175
176 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)177 __xargmatch_internal (const char *context,
178 const char *arg, const char *const *arglist,
179 const char *vallist, size_t valsize,
180 argmatch_exit_fn exit_fn)
181 {
182 ptrdiff_t res = argmatch (arg, arglist, vallist, valsize);
183 if (res >= 0)
184 /* Success. */
185 return res;
186
187 /* We failed. Explain why. */
188 argmatch_invalid (context, arg, res);
189 argmatch_valid (arglist, vallist, valsize);
190 (*exit_fn) ();
191
192 return -1; /* To please the compilers. */
193 }
194
195 /* Look for VALUE in VALLIST, an array of objects of size VALSIZE and
196 return the first corresponding argument in ARGLIST */
197 const char *
argmatch_to_argument(const char * value,const char * const * arglist,const char * vallist,size_t valsize)198 argmatch_to_argument (const char *value,
199 const char *const *arglist,
200 const char *vallist, size_t valsize)
201 {
202 size_t i;
203
204 for (i = 0; arglist[i]; i++)
205 if (!memcmp (value, vallist + valsize * i, valsize))
206 return arglist[i];
207 return NULL;
208 }
209
210 #ifdef TEST
211 /*
212 * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu>
213 */
214 char *program_name;
215
216 /* When to make backup files. */
217 enum backup_type
218 {
219 /* Never make backups. */
220 no_backups,
221
222 /* Make simple backups of every file. */
223 simple_backups,
224
225 /* Make numbered backups of files that already have numbered backups,
226 and simple backups of the others. */
227 numbered_existing_backups,
228
229 /* Make numbered backups of every file. */
230 numbered_backups
231 };
232
233 /* Two tables describing arguments (keys) and their corresponding
234 values */
235 static const char *const backup_args[] =
236 {
237 "no", "none", "off",
238 "simple", "never",
239 "existing", "nil",
240 "numbered", "t",
241 0
242 };
243
244 static const enum backup_type backup_vals[] =
245 {
246 no_backups, no_backups, no_backups,
247 simple_backups, simple_backups,
248 numbered_existing_backups, numbered_existing_backups,
249 numbered_backups, numbered_backups
250 };
251
252 int
main(int argc,const char * const * argv)253 main (int argc, const char *const *argv)
254 {
255 const char *cp;
256 enum backup_type backup_type = no_backups;
257
258 program_name = (char *) argv[0];
259
260 if (argc > 2)
261 {
262 fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", program_name);
263 exit (1);
264 }
265
266 if ((cp = getenv ("VERSION_CONTROL")))
267 backup_type = XARGMATCH ("$VERSION_CONTROL", cp,
268 backup_args, backup_vals);
269
270 if (argc == 2)
271 backup_type = XARGMATCH (program_name, argv[1],
272 backup_args, backup_vals);
273
274 printf ("The version control is `%s'\n",
275 ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals));
276
277 return 0;
278 }
279 #endif
280