clang 简单的str_replace实现
自己写的一段:
//gool char* str_replace(char* source, const char* find, const char* replace){ if (source == NULL || find == NULL || find == "") return strdup(source); int matchCount = 0; int nowIndex = 0; int findLength = strlen(find); int replaceLength = strlen(replace); int sourceLength = strlen(source); int resultLength = sourceLength; char* result; int i; for ( i = 0; i < sourceLength; i++) { if (nowIndex < findLength && source[i] == find[nowIndex]){ nowIndex++; matchCount++; } else { if (matchCount == findLength) { source[i - 1] = '\0'; nowIndex = 0; matchCount = 0; resultLength -= findLength - replaceLength; } } } nowIndex = 0; matchCount = 0; result = (char*)malloc(2 * (resultLength + 1)); for ( i = 0; i < sourceLength; i++) { if (source[i] == '\0'){ source[i] = find[0]; while (matchCount < replaceLength) { *(result + nowIndex + matchCount) = replace[matchCount]; matchCount++; } matchCount = 0; nowIndex += replaceLength; i += findLength -1; } else { *(result + nowIndex) = source[i]; nowIndex++; } } *(result + nowIndex + 1) = '\0'; return result; }
http://blog.csdn.net/glmmmm/article/details/9930969:
char *str_replace_2(const char *string, const char *substr, const char *replacement) { char *tok = NULL; char *newstr = NULL; char *oldstr = NULL; /* if either substr or replacement is NULL, duplicate string a let caller handle it */ if (substr == NULL || replacement == NULL) return strdup(string); newstr = strdup(string); while ((tok = strstr(newstr, substr))) { oldstr = newstr; newstr = (char*)malloc(strlen(oldstr) - strlen(substr) + strlen(replacement) + 1); /*failed to alloc mem, free old string and return NULL */ if (newstr == NULL) { free(oldstr); return NULL; } memcpy(newstr, oldstr, tok - oldstr); memcpy(newstr + (tok - oldstr), replacement, strlen(replacement)); memcpy(newstr + (tok - oldstr) + strlen(replacement), tok + strlen(substr), strlen(oldstr) - strlen(substr) - (tok - oldstr)); memset(newstr + strlen(oldstr) - strlen(substr) + strlen(replacement), 0, 1); free(oldstr); } return newstr; }
http://stackoverflow.com/questions/779875/what-is-the-function-to-replace-string-in-c:
char *str_replace_3(char *orig, char *rep, char *with) { char *result; // the return string char *ins; // the next insert point char *tmp; // varies int len_rep; // length of rep int len_with; // length of with int len_front; // distance between rep and end of last rep int count; // number of replacements if (!orig) return NULL; if (!rep) rep = ""; len_rep = strlen(rep); if (!with) with = ""; len_with = strlen(with); ins = orig; for (count = 0; tmp = strstr(ins, rep); ++count) { ins = tmp + len_rep; } // first time through the loop, all the variable are set correctly // from here on, // tmp points to the end of the result string // ins points to the next occurrence of rep in orig // orig points to the remainder of orig after "end of rep" tmp = result = (char*)malloc(strlen(orig) + (len_with - len_rep) * count + 1); if (!result) return NULL; while (count--) { ins = strstr(orig, rep); len_front = ins - orig; tmp = strncpy(tmp, orig, len_front) + len_front; tmp = strcpy(tmp, with) + len_with; orig += len_front + len_rep; // move to next "end of rep" } strcpy(tmp, orig); return result; }
平均测速:1. 84 clock/100000,2. 195 clock/100000,3.89 clock/100000