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 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 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 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 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 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 * 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 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