c - c 中是否有一个函数可以返回一个字符串在另一个字符串中的索引？

Question

我有2个字符数组

    char page=[4][5] = {{'a','b',' ','d','e'},  {'A',' ','C','D','E'},{'a','b','c','d','e'}, {'A','B','C','D','E'}};
    char word[5]="CDE";

我正在尝试在page中查找单词“CDE”的索引，即7和17。C中有这个功能吗？或者走一小段路。类似这样的东西，

    int indexlist[]=findindex(word, page);

Answer 1

您可以尝试以下方法:

#include <stdio.h>
#include <string.h>

int main(void) {
char page[4][5] = {{'a','b',' ','d','e'},  {'A',' ','C','D','E'},{'a','b','c','d','e'}, {'A','B','C','D','E'}};
    char word[5]="CDE";

// put all the characters in a single long string:
char buf[21];
memcpy(buf, &(page[0][0]), 20);
// and null terminate:
buf[20]='\0';
char *p;
p = buf;
while((p = strstr(p, word))!=NULL) {
  printf("found a match at offset of %d\n", (int)(p - buf));
  p+=strlen(word);
}
}

输出:

found a match at offset of 7
found a match at offset of 17