我需要实现像我自己的文件系统。 一个操作将是FindFirstFile。 我需要检查,如果调用者通过类似的东西。 ,样品* .cpp左右。 我的“文件系统”实现提供了“文件名”列表作为一个char *数组。
有没有任何Windowsfunction或任何实现此文件名匹配的源代码?
这里有很多这样的功能。 这是一个各种实现的目录 ,分为递归和非递归等。
如果你不喜欢那里的许可(或者有链接等问题),这里有一个匹配算法的一个可能的实现,至少非常接近Windows的使用:
#include <string.h> #include <iostream> bool match(char const *needle, char const *haystack) { for (; *needle != '\0'; ++needle) { switch (*needle) { case '?': if (*haystack == '\0') return false; ++haystack; break; case '*': { if (needle[1] == '\0') return true; size_t max = strlen(haystack); for (size_t i = 0; i < max; i++) if (match(needle + 1, haystack + i)) return true; return false; } default: if (*haystack != *needle) return false; ++haystack; } } return *haystack == '\0'; } #ifdef TEST #define CATCH_CONFIG_MAIN #include "catch.hpp" TEST_CASE("Matching", "[match]") { REQUIRE(match("a", "a") == true); REQUIRE(match("a", "b") == false); REQUIRE(match("a*", "a") == true); REQUIRE(match("a?", "a") == false); REQUIRE(match("a?", "ab") == true); REQUIRE(match("a*b", "ab") == true); REQUIRE(match("a*b", "acb") == true); REQUIRE(match("a*b", "abc") == false); REQUIRE(match("*a*??????a?????????a???????????????", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa") == true); } #endif
由于讨论了一些其他答案的复杂性,我会注意到,我认为这具有O(NM)复杂性和O(M)存储使用(其中N是目标字符串的大小,M是模式的大小)。
用@ masterxilo的测试对:
"*a*??????*a*?????????a???????????????", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
…在我的机器上大约3微秒内找到一个匹配。 这比典型的模式要慢很多 – 我的其他测试中的大多数在这个特定的机器上运行大约300纳秒。
与此同时,@ masterxilo的代码在同一台机器上运行需要大约11微秒,所以这个速度仍然快了3到4倍(更不用说比较小,更简单了)。
对于使用“*”和“?”的通配符名称匹配 试试这个(如果你想避免提升,使用std :: tr1 :: regex):
#include <boost/regex.hpp> #include <boost/algorithm/string/replace.hpp> using std::string; bool MatchTextWithWildcards(const string &text, string wildcardPattern, bool caseSensitive /*= true*/) { // Escape all regex special chars EscapeRegex(wildcardPattern); // Convert chars '*?' back to their regex equivalents boost::replace_all(wildcardPattern, "\\?", "."); boost::replace_all(wildcardPattern, "\\*", ".*"); boost::regex pattern(wildcardPattern, caseSensitive ? regex::normal : regex::icase); return regex_match(text, pattern); } void EscapeRegex(string ®ex) { boost::replace_all(regex, "\\", "\\\\"); boost::replace_all(regex, "^", "\\^"); boost::replace_all(regex, ".", "\\."); boost::replace_all(regex, "$", "\\$"); boost::replace_all(regex, "|", "\\|"); boost::replace_all(regex, "(", "\\("); boost::replace_all(regex, ")", "\\)"); boost::replace_all(regex, "[", "\\["); boost::replace_all(regex, "]", "\\]"); boost::replace_all(regex, "*", "\\*"); boost::replace_all(regex, "+", "\\+"); boost::replace_all(regex, "?", "\\?"); boost::replace_all(regex, "/", "\\/"); }
看看POSIX函数fnmatch
, glob
和wordexp
。
这是“C ++”,但我故意保持它几乎完全C兼容。
所有你需要做的将其转换为C是要删除template
部分,并将Pattern
和Text
更改为像char const *
。
// TEST THIS before use! I've only done limited testing. #include <stddef.h> #include <stdlib.h> #include <string.h> template<class Pattern, class Text> bool wildcard( Pattern const pat_begin, Pattern const pat_end, Text text_begin, Text const text_end) { ptrdiff_t const pat_size = pat_end - pat_begin; ptrdiff_t stackbuf[64]; size_t c = sizeof(stackbuf) / sizeof(*stackbuf); ptrdiff_t *p = stackbuf; size_t n = 0; p[n++] = 0; while (n > 0 && text_begin != text_end) { for (size_t i = 0; i < n; i++) { if (p[i] == pat_size) { p[i--] = p[--n]; continue; } switch (*(pat_begin + p[i])) { case '?': ++p[i]; break; case '*': ptrdiff_t off; off = p[i]; while (off < pat_size && *(pat_begin + off) == '*') { ++off; } if (n == c) { ptrdiff_t const *const old = p; c *= 2; if (c == 0) { ++c; } size_t const size = c * sizeof(*p); p = (ptrdiff_t *)realloc( old == stackbuf ? NULL : p, size); if (old == stackbuf) { memcpy(p, old, n * sizeof(*old)); } } p[n++] = off; break; default: if (*(pat_begin + p[i]) == *text_begin) { ++p[i]; } else { p[i--] = p[--n]; } break; } } ++text_begin; } bool success = false; if (text_begin == text_end) { while (!success && n > 0) { --n; while (p[n] != pat_size && *(pat_begin + p[n]) == '*') { ++p[n]; } if (p[n] == pat_size) { success = true; } } } if (p != stackbuf) { free(p); } return success; } bool wildcard(char const *const pattern, char const *const text) { return wildcard( pattern, pattern + (pattern ? strlen(pattern) : 0), text, text + (text ? strlen(text) : 0)); } bool wildcard(wchar_t const *const pattern, wchar_t const *const text) { return wildcard( pattern, pattern + (pattern ? wcslen(pattern) : 0), text, text + (text ? wcslen(text) : 0)); }
当然,随意使用任何你想要的代码。 🙂
Mehrdad提供的解决方案具有指数运行时间,因为它使用回溯。 它需要一秒钟才能知道"*a*??????*a*?????????a???????????????", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
是一个匹配。 也没有办法匹配一个字符串与“*”或“?” 在里面。
这是一个O(nm)的实现,我用O(n)的内存使用,其中n是表达式的长度,m是字符串的长度。 它也支持转义?,*和\。
#include <stddef.h> #include <stdlib.h> #include <string.h> /** * Wildcard matching. * See for example * http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/find_c_search_wildcard.mspx?mfr=true * * * matches any amount of any characters, * ? matches any single character. * c matches c. * No escaping of * and ? implemented (these are not allowed in windows filenames anyways). * * Backtracking O(2^n) implementation. * * from http://stackoverflow.com/questions/3300419/file-name-matching-with-wildcard * http://stackoverflow.com/a/12231681/524504 */ template<class Pattern, class Text> bool wildcard( Pattern const pat_begin, Pattern const pat_end, Text text_begin, Text const text_end) { ptrdiff_t const pat_size = pat_end - pat_begin; /* initial pattern position stack (offsets into the pattern string) and its size c */ ptrdiff_t stackbuf[64]; size_t c = sizeof(stackbuf) / sizeof(*stackbuf); /* Stack base. Can be realloc'ed to some new memory location if we need more */ ptrdiff_t *p = stackbuf; /* pointer to the location in the stack */ size_t n = 0; p[n++] = 0; /* position 0 in the stack not used */ /* text_begin updated to skip everything successfully consumed */ while (n > 0 && text_begin != text_end) { for (size_t i = 0; i < n; i++) { /* if we're at the end of the pattern, but not at the end of the * string, we might have done something wrong. */ if (p[i] == pat_size) { p[i--] = p[--n]; continue; } /* current pattern character */ switch (*(pat_begin + p[i])) { case '?': ++p[i]; break; /* simply advance pattern pointer */ case '*': ptrdiff_t off; off = p[i]; while (off < pat_size && *(pat_begin + off) == '*') { ++off; } /* if the stack is full, reallocate */ if (n == c) { ptrdiff_t const *const old = p; c *= 2; /* assert positive size * stack size never reduced anyways? */ if (c == 0) { ++c; } size_t const size = c * sizeof(*p); /* cannot use realloc to copy original stack * (ptr in realloc must be * "Pointer to a memory block previously * allocated with malloc, calloc or realloc." * must do manually */ p = (ptrdiff_t *)realloc( old == stackbuf ? NULL : p, size); if (old == stackbuf) { memcpy(p, old, n * sizeof(*old)); } } /* store offset */ p[n++] = off; break; default: /* a normal character in the pattern */ /* must be matched exactly */ if (*(pat_begin + p[i]) == *text_begin) { ++p[i]; } /* advance pattern pointer */ else /* if not, backtrack */ { p[i--] = p[--n]; } break; } } ++text_begin; } bool success = false; if (text_begin == text_end) { while (!success && n > 0) { --n; while (p[n] != pat_size && *(pat_begin + p[n]) == '*') { ++p[n]; } if (p[n] == pat_size) { success = true; } } } /* need to free stack if it was reallocated */ if (p != stackbuf) { free(p); } return success; } bool wildcard(char const *const pattern, char const *const text) { return wildcard( pattern, pattern + (pattern ? strlen(pattern) : 0), text, text + (text ? strlen(text) : 0)); } bool wildcard(wchar_t const *const pattern, wchar_t const *const text) { return wildcard( pattern, pattern + (pattern ? wcslen(pattern) : 0), text, text + (text ? wcslen(text) : 0)); } /** * Virtual Machine Style Regular Expression parsing/NFA emulation * used for wildcard matching. O(nm) algorithm. * * See http://swtch.com/~rsc/regexp/ for more on efficient RegEx parsing. * * Copyright (c) March 29, 2013 Paul Frischknecht * Can be distributed under the MIT licence, see bottom of file. */ //#define wildcard_fast_DEBUG /* define to make the alogorithm printf what its doing */ /** * Instructions are: * * star * This launches a new thread at the current position and continues with the * current thread at the next position accepting any character. * char c * Accepts exactly the character c * anychar * Accepts any character. * end * Accepts the end of the input string. */ enum InstructionType { End = 0, Star = 1, Char = 2, AnyChar = 3 }; struct Instruction { InstructionType i; int c; /* the caracter this instruction matches - undefined for non Char */ int threads; /* threads active in the given instruction */ /* * storing this here allows us to find out wether there is a thread * active at a given instruction in O(1) */ }; /** * Wildcard (file path) matching. * See for example * http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/find_c_search_wildcard.mspx?mfr=true * * * matches any amount of any characters, * ? matches any single character. * c matches c. * * Escaping of '*', '?' and '\' via '\*', '\?' and '\\' implemented. * All other bytes are recognized directly as is. * The string may not end in a single (uneven amount of) '\'. * * If text_end is 0, the text is assumed to be 0 terminated. * Same for pattern_end. The end is exclusive. * * @return A pointer to the character after the last character matched. * * Virtual machine O(nm) implementation, see http://swtch.com/~rsc/regexp/regexp2.html * * TODO Factor out the precompilation step to speed up matching multiple strings * against the same expression. */ template<class Pattern, class Text> Text wildcard_fast( Pattern const pat_begin, Pattern const pat_end, Text const text_begin, Text const text_end) { /* * give some reasonable default program size so we don't have to call * malloc in most cases */ #define DEFAULTonstack_program_SIZE 256 Instruction onstack_program[DEFAULTonstack_program_SIZE]; /* this stores the current run and next run thread list, alternating */ /* there are as most as many threads as instructions */ Instruction* onstack_threads[DEFAULTonstack_program_SIZE*2]; Instruction** threads = onstack_threads; Instruction* program = onstack_program; int program_size = sizeof(onstack_program)/sizeof(*program); Instruction* program_last_instruction = program + program_size - 1; /* program and pattern pointers */ Instruction* pp = program; Pattern patp = pat_begin; /* compile */ while ((pat_end == 0 && *patp != 0) || (pat_end != 0 && patp != pat_end)) { /* need more space */ if (pp == program_last_instruction) { Instruction* old_program = program; Instruction** old_threads = threads; int old_program_size = program_size; program_size *= 2; program = (Instruction*) malloc(program_size*sizeof(*program)); threads = (Instruction**)malloc(program_size*sizeof(*threads)*2); memcpy(program, old_program, old_program_size*sizeof(*program)); if (old_program != onstack_program) { free(old_program); free(old_threads); } program_last_instruction = program + program_size - 1; pp = pp - old_program + program; } /* parse pattern */ switch (*patp) { case '*': pp->i = Star; /* Optimize multiple stars away */ while ((pat_end == 0 || patp+1 != pat_end) && *(patp+1) == '*') patp++; break; case '?': pp->i = AnyChar; break; case '\\': pp->i = Char; pp->c = *(++patp); /* assumes string does not end in \ */ break; default: pp->i = Char; pp->c = *patp; break; } pp->threads = 0; pp++; patp++; } /* add the End instruction at the end */ program_last_instruction = pp; pp->i = End; pp->threads = 0; /* run */ Text sp = text_begin; /* input string pointer */ int n = 1, c = 0; /* next and current index */ int threadcount[2]; /* initialize */ threadcount[c] = 1; threads[0] = program; threads[0]->threads++; /* run over text */ while ((text_end == 0 && *sp != 0) || (text_end != 0 && sp != text_end)) { /* unless recreated, all threads will die */ threadcount[n] = 0; /* run over threads */ for (int i = 0; i < threadcount[c]; i++) { Instruction* inst = threads[2*i+c]; switch (inst->i) { case End: /* we may not reach end early */ /* kill this thread without recrating it */ inst->threads--; continue; /* with for loop */ case Char: if (*sp != inst->c) { /* if the character is not matched, kill this thread */ inst->threads--; continue; } break; case Star: /* spawn off additional thread at current location */ if (inst->threads == 1) { /* only if there's noone active there yet */ threads[2*(threadcount[n]++)+n] = inst; inst->threads++; } break; } /* * common actions: increase program counter for current thread, * decrese amount of threads in last (current) instruction. */ inst->threads--; inst++; inst->threads++; /* respawn at new location in next iteration */ threads[2*(threadcount[n]++)+n] = inst; if (inst->i == Star && (inst+1)->threads == 0) { /* * already follow no-match option to give us * more stuff to do */ threads[2*(threadcount[n]++)+n] = inst+1; (inst+1)->threads++; } #ifdef wildcard_fast_DEBUG for (int i = 0 ; i < threadcount[n]; i++) { printf("thread %d at %d.\n", i, threads[2*i+n]-program); } #endif } #ifdef wildcard_fast_DEBUG const char *ns[] = { "end", "star", "char", "anychar", }; for (Instruction* p = program; p->i; p++) { printf("%d. %s %c (%d threads)\n", p-program, ns[p->i], p->i == Char ? p->c : ' ', p->threads); } #endif /* swap next and current and advance */ n = c; c = !c; sp++; } /* * if there is no thread active in the End instruction when the * end of the input was reached, this was no match */ if (program_last_instruction->threads == 0) sp = 0; if (program != onstack_program) { /* only need to free if we used malloc */ free(program); free(threads); } return sp; } char const* wildcard_fast( char const *const pattern, char const *const text) { return wildcard_fast( pattern, (const char*)0, text, (const char*)0); } wchar_t const* wildcard_fast( wchar_t const *const pattern, wchar_t const *const text) { return wildcard_fast( pattern, (const wchar_t*)0, text, (const wchar_t*)0); } /* tests */ #ifndef INCLUDE_IMPLEMENTATION /* * I just include this file in my projects and define this. * That works well for simple algorithms like this */ #include <stdio.h> #include <time.h> int main() { struct { char* p; char* t; bool expected_result; } test[] = { { "", "", true }, { "a", "", false }, { "", "a", false }, { "a", "a", true }, { "****.txt", "hello.txt", true }, { "*.txt", "hello.tzt", false }, { "*.t?t*", "hello.tzt", true }, { "*.*", "hi.there", true }, /* the wildcard implementation will fail this as it doesn't understand escaping */ { "\\*who\\?\\?.*\\\\", "*who??.there\\", true }, /* these take extraordinaryly long on the O(2^n) implementation */ { "**a*************************??????***a************************?????????a???????????????", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", true }, /* runs a bit better if we omit the extra *'s. The fast implementation already optimizes these away. */ { "*a*??????*a*?????????a???????????????", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", true }, {0,0} /* marks end of tests */ }; int t0 = clock(); const char* result; const char* r[] = {"no match", "match"}; for (int i = 0; test[i].p; i++) { printf("=== Test %d: Matching '%s' against '%s'...===\n", i, test[i].t, test[i].p); /* wildcard_fast */ t0 = clock(); result = wildcard_fast(test[i].p, test[i].t); printf(" wildcard_fast (took %d ms):\n", clock()-t0); if (!!result != test[i].expected_result) printf(" Test failed (reported %s instead of expected %s).\n", r[!!result], r[test[i].expected_result]); else if (result) { printf(" %s\n", test[i].t); printf(" %*.c\n", result-test[i].t+1, '^'); } else printf(" No match.\n"); /* wildcard */ t0 = clock(); result = (const char*) wildcard(test[i].p, test[i].t); printf(" wildcard (took %d ms):\n", clock()-t0); if (!!result != test[i].expected_result) printf(" Test failed (reported %s instead of expected %s).\n", r[!!result], r[test[i].expected_result]); else if (result) printf(" Match.\n"); else printf(" No match.\n"); printf("\n"); } } #endif /* * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated * documentation files (the "Software"), to deal in the * Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, * sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall * be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY * KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
这使用虚拟机方法。 有关效率正则表达式解析的更多信息,请参阅http://swtch.com/~rsc/regexp/ 。
PathMatchSpec 。 虽然它受到MAX_PATH
限制(即可以接受不超过260个字符)。 你可能会更好地实施自己的匹配器; 这不是很多的代码。