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//#define _CRT_SECURE_NO_WARNINGS //关闭安全
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if 0
void tihu(char** ppstr, char* old, char* new_str)
{
int pplen = strlen(*ppstr);//原字符串长度
int olen = strlen(old);//被替换的长度
int nlen = strlen(new_str);//替换的长度
char* p1 = *ppstr; //创建2个指针保存原字符串的地址
char* p2 = *ppstr;
while (*p1 != '\0')//循环
{
*p1 = *p2;// 2指针错位
int flag = 1; //假设找到 1
for (int i = 0; i < olen; i++)
{
if (p2[i] != old[i] || p2[i] == '\0')//寻找
{
flag = 0;//找不到
break;//跳出
}
}
if (flag == 0)
{
p1++;
p2++;
}
else
{
int n = p1 - *ppstr;//确认位置
int m = p2 - *ppstr;
*ppstr = recalloc(*ppstr, pplen + nlen - olen + 1, 1);//扩展内存+1处理'\0'
p1 = *ppstr + n;//找回位置
p2 = *ppstr + m;
for (char* p = p2 + strlen(p2); p >= p2; p--)//移动字符串
{
*(p + nlen - olen) = *p;
}
for (int i = 0; i < nlen; i++)//拷贝
{
p2[i] = new_str[i];
}
}
}
}
#endif
void replace_str(char **str, const char *substr, const char *newstr)
{
int i;
int src_len = strlen(*str);
int sub_len = strlen(substr);
int new_len = strlen(newstr);
char *pstr = *str;
unsigned int len, pos;
len = src_len;
while (*pstr) {
for (i = 0; i < sub_len; i++) {
if (*pstr && pstr[i] != substr[i])
break;
}
if (src_len - (pstr-*str) < sub_len)
break;
if (i >= sub_len) {
pos = pstr - *str;
//if (sub_len < new_len) {
*str = (char *)realloc(*str, src_len + new_len - sub_len + 1);
if (!(*str))
return;
pstr = *str + pos;
memmove(pstr + new_len, pstr+sub_len, src_len - pos);
src_len = src_len + new_len - sub_len;
memcpy(pstr, newstr, new_len);
pstr += new_len;
//}
continue;
}
pstr++;
}
(*str)[src_len] = 0;
}
//void main()
int main()
{
int slen = strlen("aaaaaaaa like aaaaa like aaaaaaaa"); //原字符串长度
char *p = (char *)malloc(slen + 1);// 分配内存空间
strcpy(p, "aaaaaaaa CCCC aaaaa CCCC aaaaaaaa");//拷贝字符串
//tihu(&p, "CCCC", "bbbb bbbb bbbb bbbb");//替换
printf("Before replace: %s\n", p);
replace_str(&p, "CCCC", "bbbb bbbb bbbb bbbb");
//replace_str(&p, "CCCC", "abc");
printf("%s\n", p);
//system("pause");
//
return 0;
}