字符窜分割与替换函数

string_split_replace.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
char *replace(char *dst, const char *src, const char *rep_from, const char *rep_by)
{
    //*dst = 0;
    const char *start = src;
    char *end;
    size_t len = strlen(rep_from);
 
    while(end = strstr(start, rep_from)) {
        strncat(dst, start, end - start);
        strcat(dst, rep_by);
        start = end + len;
    }
    strcat(dst, start);
 
    return dst;
}
 
int splitcat(char *dst, char *src, const char *split)
{
    char *end;
    if(end = strstr(src, split)) {
        strncat(dst, src, end - src);
        return end - src + strlen(split);
    }
    else {
        strcat(dst, src);
    }
    return 0;
}
 
char *split(char* **dst, char *src, const char *split)
{
    int len = strlen(src) + 1;
    char *mem = malloc(len);
    memset(mem, 0, len);
 
    char *tmp = mem;
 
    char* *addr = (char* *) malloc(8);
 
    int index = 0;
    int pos;
    while(pos = splitcat(tmp, src, split)) {
        addr[index++] = tmp;
        realloc(addr, (index + 2) * 4);
        src += pos;
        tmp += pos;
    }
    addr[index] = tmp;
    // end flag
    addr[index + 1] = 0;
 
    *dst = addr;
 
    return mem;
}
 
int main()
{
    // split
    char *src = "$$pal$$123$$4561$$999$$aaaa$$1234$$";
    printf("origin str:%s\n", src);
 
    char **addr;
    char *mem = split(&addr, src, "$$");
 
    printf("split result:\n");
    int i = 0;
    while(*addr) {
        printf("addr[%d] = %s\n", i, *addr);
        ++addr;
        ++i;
    }
 
    free(mem);
    free(addr);
 
    // replace
    char dst[100] = {0};
    replace(dst, src, "$$", "__");
    printf("replace result:%s\n", dst);
 
    return 0;
}