1 /* argmatch.c -- find a match for a string in an array 2 3 Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2015 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 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 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 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 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 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 * 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 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