字元串操作( 二 )

4、 strcmp()功能：串比较。用法：int strcmp(char *str1, char *str2);看Asic码，str1>str2，返回值 > 0；两串相等，返回0 。举例如下：#include <string.h> #include <stdio.h>int main(void) { char *buf1 = "aaa", *buf2 = "bbb", *buf3 = "ccc"; int ptr; ptr = strcmp(buf2, buf1); if (ptr > 0) printf("buffer 2 is greater than buffer 1\n"); else printf("buffer 2 is less than buffer 1\n"); ptr = strcmp(buf2, buf3); if (ptr > 0) printf("buffer 2 is greater than buffer 3\n"); else printf("buffer 2 is less than buffer 3\n"); return 0; } 5、strcpy()功能：串拷贝。用法：char *strcpy(char *str1, char *str2);举例如下：#include <stdio.h> #include <string.h>int main(void) { char string[10]; char *str1 = "abcdefghi"; strcpy(string, str1); printf("%s\n", string); return 0; } 6、strerror()功能：返回指向错误信息字元串的指针。用法:：char *strerror(int errnum);举例如下：#include <stdio.h> #include <errno.h>int main(void) { char *buffer; buffer = strerror(errno); printf("Error: %s\n", buffer); return 0; } 7、strnset()功能：将一个串中的所有字元都设为指定字元。用法：char *strnset(char *str, char ch, unsigned n);举例如下：#include <stdio.h> #include <string.h>int main(void) { char *string = "abcdefghijklmnopqrstuvwxyz"; char letter = 'x'; printf("string before strnset: %s\n", string); strnset(string, letter, 13); printf("string after strnset: %s\n", string); return 0; } 8、strpbrk()功能：在串中查找给定字元集中的字元。用法：char *strpbrk(char *str1, char *str2);举例如下：#include <stdio.h> #include <string.h>int main(void) { char *string1 = "abcdefghijklmnopqrstuvwxyz"; char *string2 = "onm"; char *ptr; ptr = strpbrk(string1, string2); if (ptr) printf("strpbrk found first character: %c\n", *ptr); else printf("strpbrk didn't find character in set\n"); return 0; }