函数名: strtok 
 功  能: 查找由在第二个串中指定的分界符分隔开的单词 
 用  法: #include <string.h> 
         char *strtok(char *str1, char *str2); 
 程序例: 
#include <string.h> 
 #include <stdio.h> 
int main(void) 
 { 
    char input[16] = "abc,d"; 
    char *p; 
   /* strtok places a NULL terminator 
    in front of the token, if found */ 
    p = strtok(input, ","); 
    if (p)   printf("%s\n", p); 
   /* A second call to strtok using a NULL 
    as the first parameter returns a pointer 
    to the character following the token  */ 
    p = strtok(NULL, ","); 
    if (p)   printf("%s\n", p); 
    return 0; 
 }