| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2017 Philippe Proulx <pproulx@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #define _LGPL_SOURCE |
| 8 | #include <stdlib.h> |
| 9 | #include <string.h> |
| 10 | #include <stdbool.h> |
| 11 | #include <assert.h> |
| 12 | |
| 13 | #include "common/strutils.h" |
| 14 | |
| 15 | enum star_glob_pattern_type_flags { |
| 16 | STAR_GLOB_PATTERN_TYPE_FLAG_NONE = 0, |
| 17 | STAR_GLOB_PATTERN_TYPE_FLAG_PATTERN = 1, |
| 18 | STAR_GLOB_PATTERN_TYPE_FLAG_END_ONLY = 2, |
| 19 | }; |
| 20 | |
| 21 | static |
| 22 | enum star_glob_pattern_type_flags strutils_test_glob_pattern(const char *pattern) |
| 23 | { |
| 24 | enum star_glob_pattern_type_flags ret = |
| 25 | STAR_GLOB_PATTERN_TYPE_FLAG_NONE; |
| 26 | const char *p; |
| 27 | |
| 28 | assert(pattern); |
| 29 | |
| 30 | for (p = pattern; *p != '\0'; p++) { |
| 31 | switch (*p) { |
| 32 | case '*': |
| 33 | ret = STAR_GLOB_PATTERN_TYPE_FLAG_PATTERN; |
| 34 | |
| 35 | if (p[1] == '\0') { |
| 36 | ret |= STAR_GLOB_PATTERN_TYPE_FLAG_END_ONLY; |
| 37 | } |
| 38 | |
| 39 | goto end; |
| 40 | case '\\': |
| 41 | p++; |
| 42 | |
| 43 | if (*p == '\0') { |
| 44 | goto end; |
| 45 | } |
| 46 | break; |
| 47 | default: |
| 48 | break; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | end: |
| 53 | return ret; |
| 54 | } |
| 55 | |
| 56 | /* |
| 57 | * Returns true if `pattern` is a star-only globbing pattern, that is, |
| 58 | * it contains at least one non-escaped `*`. |
| 59 | */ |
| 60 | bool strutils_is_star_glob_pattern(const char *pattern) |
| 61 | { |
| 62 | return strutils_test_glob_pattern(pattern) & |
| 63 | STAR_GLOB_PATTERN_TYPE_FLAG_PATTERN; |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Returns true if `pattern` is a globbing pattern with a globbing, |
| 68 | * non-escaped star only at its very end. |
| 69 | */ |
| 70 | bool strutils_is_star_at_the_end_only_glob_pattern(const char *pattern) |
| 71 | { |
| 72 | return strutils_test_glob_pattern(pattern) & |
| 73 | STAR_GLOB_PATTERN_TYPE_FLAG_END_ONLY; |
| 74 | } |
| 75 | |
| 76 | static inline |
| 77 | bool at_end_of_pattern(const char *p, const char *pattern, size_t pattern_len) |
| 78 | { |
| 79 | return (p - pattern) == pattern_len || *p == '\0'; |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * Globbing matching function with the star feature only (`?` and |
| 84 | * character sets are not supported). This matches `candidate` (plain |
| 85 | * string) against `pattern`. A literal star can be escaped with `\` in |
| 86 | * `pattern`. |
| 87 | * |
| 88 | * `pattern_len` or `candidate_len` can be greater than the actual |
| 89 | * string length of `pattern` or `candidate` if the string is |
| 90 | * null-terminated. |
| 91 | */ |
| 92 | bool strutils_star_glob_match(const char *pattern, size_t pattern_len, |
| 93 | const char *candidate, size_t candidate_len) { |
| 94 | const char *retry_c = candidate, *retry_p = pattern, *c, *p; |
| 95 | bool got_a_star = false; |
| 96 | |
| 97 | retry: |
| 98 | c = retry_c; |
| 99 | p = retry_p; |
| 100 | |
| 101 | /* |
| 102 | * The concept here is to retry a match in the specific case |
| 103 | * where we already got a star. The retry position for the |
| 104 | * pattern is just after the most recent star, and the retry |
| 105 | * position for the candidate is the character following the |
| 106 | * last try's first character. |
| 107 | * |
| 108 | * Example: |
| 109 | * |
| 110 | * candidate: hi ev every onyx one |
| 111 | * ^ |
| 112 | * pattern: hi*every*one |
| 113 | * ^ |
| 114 | * |
| 115 | * candidate: hi ev every onyx one |
| 116 | * ^ |
| 117 | * pattern: hi*every*one |
| 118 | * ^ |
| 119 | * |
| 120 | * candidate: hi ev every onyx one |
| 121 | * ^ |
| 122 | * pattern: hi*every*one |
| 123 | * ^ |
| 124 | * |
| 125 | * candidate: hi ev every onyx one |
| 126 | * ^ |
| 127 | * pattern: hi*every*one |
| 128 | * ^ MISMATCH |
| 129 | * |
| 130 | * candidate: hi ev every onyx one |
| 131 | * ^ |
| 132 | * pattern: hi*every*one |
| 133 | * ^ |
| 134 | * |
| 135 | * candidate: hi ev every onyx one |
| 136 | * ^^ |
| 137 | * pattern: hi*every*one |
| 138 | * ^^ |
| 139 | * |
| 140 | * candidate: hi ev every onyx one |
| 141 | * ^ ^ |
| 142 | * pattern: hi*every*one |
| 143 | * ^ ^ MISMATCH |
| 144 | * |
| 145 | * candidate: hi ev every onyx one |
| 146 | * ^ |
| 147 | * pattern: hi*every*one |
| 148 | * ^ MISMATCH |
| 149 | * |
| 150 | * candidate: hi ev every onyx one |
| 151 | * ^ |
| 152 | * pattern: hi*every*one |
| 153 | * ^ MISMATCH |
| 154 | * |
| 155 | * candidate: hi ev every onyx one |
| 156 | * ^ |
| 157 | * pattern: hi*every*one |
| 158 | * ^ |
| 159 | * |
| 160 | * candidate: hi ev every onyx one |
| 161 | * ^^ |
| 162 | * pattern: hi*every*one |
| 163 | * ^^ |
| 164 | * |
| 165 | * candidate: hi ev every onyx one |
| 166 | * ^ ^ |
| 167 | * pattern: hi*every*one |
| 168 | * ^ ^ |
| 169 | * |
| 170 | * candidate: hi ev every onyx one |
| 171 | * ^ ^ |
| 172 | * pattern: hi*every*one |
| 173 | * ^ ^ |
| 174 | * |
| 175 | * candidate: hi ev every onyx one |
| 176 | * ^ ^ |
| 177 | * pattern: hi*every*one |
| 178 | * ^ ^ |
| 179 | * |
| 180 | * candidate: hi ev every onyx one |
| 181 | * ^ |
| 182 | * pattern: hi*every*one |
| 183 | * ^ |
| 184 | * |
| 185 | * candidate: hi ev every onyx one |
| 186 | * ^ |
| 187 | * pattern: hi*every*one |
| 188 | * ^ MISMATCH |
| 189 | * |
| 190 | * candidate: hi ev every onyx one |
| 191 | * ^ |
| 192 | * pattern: hi*every*one |
| 193 | * ^ |
| 194 | * |
| 195 | * candidate: hi ev every onyx one |
| 196 | * ^^ |
| 197 | * pattern: hi*every*one |
| 198 | * ^^ |
| 199 | * |
| 200 | * candidate: hi ev every onyx one |
| 201 | * ^ ^ |
| 202 | * pattern: hi*every*one |
| 203 | * ^ ^ MISMATCH |
| 204 | * |
| 205 | * candidate: hi ev every onyx one |
| 206 | * ^ |
| 207 | * pattern: hi*every*one |
| 208 | * ^ MISMATCH |
| 209 | * |
| 210 | * candidate: hi ev every onyx one |
| 211 | * ^ |
| 212 | * pattern: hi*every*one |
| 213 | * ^ MISMATCH |
| 214 | * |
| 215 | * candidate: hi ev every onyx one |
| 216 | * ^ |
| 217 | * pattern: hi*every*one |
| 218 | * ^ MISMATCH |
| 219 | * |
| 220 | * candidate: hi ev every onyx one |
| 221 | * ^ |
| 222 | * pattern: hi*every*one |
| 223 | * ^ MISMATCH |
| 224 | * |
| 225 | * candidate: hi ev every onyx one |
| 226 | * ^ |
| 227 | * pattern: hi*every*one |
| 228 | * ^ |
| 229 | * |
| 230 | * candidate: hi ev every onyx one |
| 231 | * ^^ |
| 232 | * pattern: hi*every*one |
| 233 | * ^^ |
| 234 | * |
| 235 | * candidate: hi ev every onyx one |
| 236 | * ^ ^ |
| 237 | * pattern: hi*every*one |
| 238 | * ^ ^ |
| 239 | * |
| 240 | * candidate: hi ev every onyx one |
| 241 | * ^ ^ |
| 242 | * pattern: hi*every*one |
| 243 | * ^ ^ SUCCESS |
| 244 | */ |
| 245 | while ((c - candidate) < candidate_len && *c != '\0') { |
| 246 | assert(*c); |
| 247 | |
| 248 | if (at_end_of_pattern(p, pattern, pattern_len)) { |
| 249 | goto end_of_pattern; |
| 250 | } |
| 251 | |
| 252 | switch (*p) { |
| 253 | case '*': |
| 254 | got_a_star = true; |
| 255 | |
| 256 | /* |
| 257 | * Our first try starts at the current candidate |
| 258 | * character and after the star in the pattern. |
| 259 | */ |
| 260 | retry_c = c; |
| 261 | retry_p = p + 1; |
| 262 | |
| 263 | if (at_end_of_pattern(retry_p, pattern, pattern_len)) { |
| 264 | /* |
| 265 | * Star at the end of the pattern at |
| 266 | * this point: automatic match. |
| 267 | */ |
| 268 | return true; |
| 269 | } |
| 270 | |
| 271 | goto retry; |
| 272 | case '\\': |
| 273 | /* Go to escaped character. */ |
| 274 | p++; /* Fallthrough */ |
| 275 | |
| 276 | /* |
| 277 | * Fall through the default case which will |
| 278 | * compare the escaped character now. |
| 279 | */ |
| 280 | default: |
| 281 | if (at_end_of_pattern(p, pattern, pattern_len) || |
| 282 | *c != *p) { |
| 283 | end_of_pattern: |
| 284 | /* Character mismatch OR end of pattern. */ |
| 285 | if (!got_a_star) { |
| 286 | /* |
| 287 | * We didn't get any star yet, |
| 288 | * so this first mismatch |
| 289 | * automatically makes the whole |
| 290 | * test fail. |
| 291 | */ |
| 292 | return false; |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * Next try: next candidate character, |
| 297 | * original pattern character (following |
| 298 | * the most recent star). |
| 299 | */ |
| 300 | retry_c++; |
| 301 | goto retry; |
| 302 | } |
| 303 | break; |
| 304 | } |
| 305 | |
| 306 | /* Next pattern and candidate characters. */ |
| 307 | c++; |
| 308 | p++; |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * We checked every candidate character and we're still in a |
| 313 | * success state: the only pattern character allowed to remain |
| 314 | * is a star. |
| 315 | */ |
| 316 | if (at_end_of_pattern(p, pattern, pattern_len)) { |
| 317 | return true; |
| 318 | } |
| 319 | |
| 320 | p++; |
| 321 | return p[-1] == '*' && at_end_of_pattern(p, pattern, pattern_len); |
| 322 | } |