c - c 中 strtok() 的使用显示警告并返回段错误(核心已转储)

Question

我正在学习 C 字符串操作并使用 strtok() 函数。我的代码以警告结束，然后输出是段错误。

这是源代码(在文件 token3.c 中):

#include <stdio.h>
#include <string.h>
int main() {
    char str[] = "aa.bb.cc.dd.ee.ff";
    char *p;
    p = strtok(str, '.');
    while (p != NULL) {
        printf("%s\n", p);
        p = strtok(NULL, '.');
    }
    return 0;
}

编译期间的警告:

token3.c: In function ‘main’:
token3.c:6:15: warning: passing argument 2 of ‘strtok’ makes pointer from integer without a cast [-Wint-conversion]
      p=strtok(str,'.');
                   ^~~
In file included from token3.c:2:0:
/usr/include/string.h:335:14: note: expected ‘const char * restrict’ but argument is of type ‘int’
extern char *strtok (char *__restrict __s, const char *__restrict __delim)
               ^~~~~~
token3.c:9:17: warning: passing argument 2 of ‘strtok’ makes pointer from integer without a cast [-Wint-conversion]
    p=strtok(NULL,'.');<br>
                  ^~~
In file included from token3.c:2:0:
/usr/include/string.h:335:14: note: expected ‘const char * restrict’
but argument is of type ‘int’
    extern char *strtok (char *__restrict __s, const char *__restrict __delim)
                                               ^~~~~~<

预期输出:

aa
bb
cc
dd
ee
ff

实际输出:

Segmentation fault(core dumped)

Answer 1

这是一个错误，只是替换

strtok(str,'.');

与

strtok(str,".");

strtok() 的第二个参数表示分隔符并期望类型

const char *

所以必须用“”括起来。

strtok() 的语法

char *strtok(char *str, const char *delim);