/* 范例：7-16 */
#include <stdio.h>
#include <string.h>
void main()
{
  printf("=====strcmp======\n");
  char *s1 = "abc";
  char *s2 = "arc";
  printf("strcmp: %d\n",strcmp(s1,s2));
  if(strcmp(s1,s2)<0)
    printf("strcmp(s1,s2)<0\n");
  char *s3 = "aar";
  char *s4 = "aaadef";
  printf("strcmp: %d\n",strcmp(s3,s4));
  if(strcmp(s3,s4)>0)
    printf("strcmp(s3,s4)>0\n");
  char *s5 = "abcd";
  char *s6 = "abcd";
  printf("strcmp: %d\n",strcmp(s5,s6));
  if(strcmp(s5,s6)==0)
    printf("strcmp(s5,s6)=0\n");
  printf("=====strlen======\n");
  printf("strlen(s6): %d\n",strlen(s6));
  printf("=====strchr======\n");
  char *string = "tiger is brave";
  char *ptr, c = 'e';
  ptr = strchr(string,c);
  printf("strchr(string,c): %c\n",*ptr);
  if (*ptr==c)
    printf("字符'%c'在字符串tiger is brave的第%d個位置\n", c, \ (ptr-string)+1);
  printf("=====strstr======\n");
  char *str1 = "tiger is brave", *str2 = "ra", *strptr;
  strptr = strstr(str1, str2);
  printf("%s\n", strptr);  /* 輸出字符指針strptr所指向地址到'\0'的字符串 */
  getchar();
}

程序執行結果：
=====strcmp======
strcmp: -16
strcmp(s1,s2)<0
strcmp: 17
strcmp(s3,s4)>0
strcmp: 0
strcmp(s5,s6)=0
=====strlen======
strlen(s6): 4
=====strchr======
strchr(string,c): e
字符'e'在字符串tiger is brave的第4個位置
=====strstr======
rave