1 /* argmatch.c -- find a match for a string in an array 2 3 Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2020 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 <https://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 #define _(msgid) gettext (msgid) 33 34 #include "error.h" 35 #include "quotearg.h" 36 #include "getprogname.h" 37 38 #if USE_UNLOCKED_IO 39 # include "unlocked-io.h" 40 #endif 41 42 /* When reporting an invalid argument, show nonprinting characters 43 by using the quoting style ARGMATCH_QUOTING_STYLE. Do not use 44 literal_quoting_style. */ 45 #ifndef ARGMATCH_QUOTING_STYLE 46 # define ARGMATCH_QUOTING_STYLE locale_quoting_style 47 #endif 48 49 /* Non failing version of argmatch call this function after failing. */ 50 #ifndef ARGMATCH_DIE 51 # include "exitfail.h" 52 # define ARGMATCH_DIE exit (exit_failure) 53 #endif 54 55 #ifdef ARGMATCH_DIE_DECL 56 ARGMATCH_DIE_DECL; 57 #endif 58 59 static void 60 __argmatch_die (void) 61 { 62 ARGMATCH_DIE; 63 } 64 65 /* Used by XARGMATCH and XARGCASEMATCH. See description in argmatch.h. 66 Default to __argmatch_die, but allow caller to change this at run-time. */ 67 argmatch_exit_fn argmatch_die = __argmatch_die; 68 69 70 /* If ARG is an unambiguous match for an element of the 71 NULL-terminated array ARGLIST, return the index in ARGLIST 72 of the matched element, else -1 if it does not match any element 73 or -2 if it is ambiguous (is a prefix of more than one element). 74 75 If VALLIST is none null, use it to resolve ambiguities limited to 76 synonyms, i.e., for 77 "yes", "yop" -> 0 78 "no", "nope" -> 1 79 "y" is a valid argument, for 0, and "n" for 1. */ 80 81 ptrdiff_t 82 argmatch (const char *arg, const char *const *arglist, 83 const void *vallist, size_t valsize) 84 { 85 size_t i; /* Temporary index in ARGLIST. */ 86 size_t arglen; /* Length of ARG. */ 87 ptrdiff_t matchind = -1; /* Index of first nonexact match. */ 88 bool ambiguous = false; /* If true, multiple nonexact match(es). */ 89 90 arglen = strlen (arg); 91 92 /* Test all elements for either exact match or abbreviated matches. */ 93 for (i = 0; arglist[i]; i++) 94 { 95 if (!strncmp (arglist[i], arg, arglen)) 96 { 97 if (strlen (arglist[i]) == arglen) 98 /* Exact match found. */ 99 return i; 100 else if (matchind == -1) 101 /* First nonexact match found. */ 102 matchind = i; 103 else 104 { 105 /* Second nonexact match found. */ 106 if (vallist == NULL 107 || memcmp ((char const *) vallist + valsize * matchind, 108 (char const *) vallist + valsize * i, valsize)) 109 { 110 /* There is a real ambiguity, or we could not 111 disambiguate. */ 112 ambiguous = true; 113 } 114 } 115 } 116 } 117 if (ambiguous) 118 return -2; 119 else 120 return matchind; 121 } 122 123 /* Error reporting for argmatch. 124 CONTEXT is a description of the type of entity that was being matched. 125 VALUE is the invalid value that was given. 126 PROBLEM is the return value from argmatch. */ 127 128 void 129 argmatch_invalid (const char *context, const char *value, ptrdiff_t problem) 130 { 131 char const *format = (problem == -1 132 ? _("invalid argument %s for %s") 133 : _("ambiguous argument %s for %s")); 134 135 error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value), 136 quote_n (1, context)); 137 } 138 139 /* List the valid arguments for argmatch. 140 ARGLIST is the same as in argmatch. 141 VALLIST is a pointer to an array of values. 142 VALSIZE is the size of the elements of VALLIST */ 143 void 144 argmatch_valid (const char *const *arglist, 145 const void *vallist, size_t valsize) 146 { 147 size_t i; 148 const char *last_val = NULL; 149 150 /* We try to put synonyms on the same line. The assumption is that 151 synonyms follow each other */ 152 fputs (_("Valid arguments are:"), stderr); 153 for (i = 0; arglist[i]; i++) 154 if ((i == 0) 155 || memcmp (last_val, (char const *) vallist + valsize * i, valsize)) 156 { 157 fprintf (stderr, "\n - %s", quote (arglist[i])); 158 last_val = (char const *) vallist + valsize * i; 159 } 160 else 161 { 162 fprintf (stderr, ", %s", quote (arglist[i])); 163 } 164 putc ('\n', stderr); 165 } 166 167 /* Never failing versions of the previous functions. 168 169 CONTEXT is the context for which argmatch is called (e.g., 170 "--version-control", or "$VERSION_CONTROL" etc.). Upon failure, 171 calls the (supposed never to return) function EXIT_FN. */ 172 173 ptrdiff_t 174 __xargmatch_internal (const char *context, 175 const char *arg, const char *const *arglist, 176 const void *vallist, size_t valsize, 177 argmatch_exit_fn exit_fn) 178 { 179 ptrdiff_t res = argmatch (arg, arglist, vallist, valsize); 180 if (res >= 0) 181 /* Success. */ 182 return res; 183 184 /* We failed. Explain why. */ 185 argmatch_invalid (context, arg, res); 186 argmatch_valid (arglist, vallist, valsize); 187 (*exit_fn) (); 188 189 return -1; /* To please the compilers. */ 190 } 191 192 /* Look for VALUE in VALLIST, an array of objects of size VALSIZE and 193 return the first corresponding argument in ARGLIST */ 194 const char * 195 argmatch_to_argument (const void *value, 196 const char *const *arglist, 197 const void *vallist, size_t valsize) 198 { 199 size_t i; 200 201 for (i = 0; arglist[i]; i++) 202 if (!memcmp (value, (char const *) vallist + valsize * i, valsize)) 203 return arglist[i]; 204 return NULL; 205 } 206 207 #ifdef TEST 208 /* 209 * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu> 210 */ 211 212 /* When to make backup files. */ 213 enum backup_type 214 { 215 /* Never make backups. */ 216 no_backups, 217 218 /* Make simple backups of every file. */ 219 simple_backups, 220 221 /* Make numbered backups of files that already have numbered backups, 222 and simple backups of the others. */ 223 numbered_existing_backups, 224 225 /* Make numbered backups of every file. */ 226 numbered_backups 227 }; 228 229 /* Two tables describing arguments (keys) and their corresponding 230 values */ 231 static const char *const backup_args[] = 232 { 233 "no", "none", "off", 234 "simple", "never", 235 "existing", "nil", 236 "numbered", "t", 237 0 238 }; 239 240 static const enum backup_type backup_vals[] = 241 { 242 no_backups, no_backups, no_backups, 243 simple_backups, simple_backups, 244 numbered_existing_backups, numbered_existing_backups, 245 numbered_backups, numbered_backups 246 }; 247 248 int 249 main (int argc, const char *const *argv) 250 { 251 const char *cp; 252 enum backup_type backup_type = no_backups; 253 254 if (argc > 2) 255 { 256 fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", getprogname ()); 257 exit (1); 258 } 259 260 if ((cp = getenv ("VERSION_CONTROL"))) 261 backup_type = XARGMATCH ("$VERSION_CONTROL", cp, 262 backup_args, backup_vals); 263 264 if (argc == 2) 265 backup_type = XARGMATCH (getprogname (), argv[1], 266 backup_args, backup_vals); 267 268 printf ("The version control is '%s'\n", 269 ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals)); 270 271 return 0; 272 } 273 #endif 274