1.函数名: stpcpy
功 能: 拷贝一个字符串到另一个
用 法: char *stpcpy(char *destin, char *source);
程序例:

#include
#include

int main(void)
{
char string[10];
char *str1 = "abcdefghi";

stpcpy(string, str1);
printf("%s\n", string);
return 0;
}

2.函数名: strcat
功 能: 字符串拼接函数
用 法: char *strcat(char *destin, char *source);
程序例:

#include
#include

int main(void)
{
char destination[25];
char *blank = " ", *c = "C++", *Borland = "Borland";

strcpy(destination, Borland);
strcat(destination, blank);
strcat(destination, c);

printf("%s\n", destination);
return 0;
}

3.函数名: strchr

功 能: 在一个串中查找给定字符的第一个匹配之处\
用 法: char *strchr(char *str, char c);
程序例:

#include
#include

int main(void)
{
char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");
ptr = strchr(string, c);
if (ptr)
printf("The character %c is at position: %d\n", c, ptr-string);
else
printf("The character was not found\n");
return 0;
}

4.函数名: 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
程序例:

#include
#include

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.函数名: strncmpi
功 能: 将一个串中的一部分与另一个串比较, 不管大小写
用 法: int strncmpi(char *str1, char *str2, unsigned maxlen);
程序例:

#include
#include

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = strcmpi(buf2, buf1);

if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
printf("buffer 2 equals buffer 1\n");

return 0;
}

6.函数名: strcpy
功 能: 串拷贝
用 法: char *strcpy(char *str1, char *str2);
程序例:

#include
#include

int main(void)
{
char string[10];
char *str1 = "abcdefghi";

strcpy(string, str1);
printf("%s\n", string);
return 0;
}

7.函数名: strcspn
功 能: 在串中查找第一个给定字符集内容的段
用 法: int strcspn(char *str1, char *str2);
程序例:

#include
#include
#include

int main(void)
{
char *string1 = "1234567890";
char *string2 = "747DC8";
int length;

length = strcspn(string1, string2);
printf("Character where strings intersect is at position %d\n", length);

return 0;
}

8.函数名: strdup
功 能: 将串拷贝到新建的位置处
用 法: char *strdup(char *str);
程序例:

#include
#include
#include

int main(void)
{
char *dup_str, *string = "abcde";

dup_str = strdup(string);
printf("%s\n", dup_str);
free(dup_str);

return 0;
}

9.函数名: stricmp
功 能: 以大小写不敏感方式比较两个串
用 法: int stricmp(char *str1, char *str2);
程序例:

#include
#include

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = stricmp(buf2, buf1);

if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
printf("buffer 2 equals buffer 1\n");

return 0;
}

10.函数名: strerror
功 能: 返回指向错误信息字符串的指针
用 法: char *strerror(int errnum);
程序例:

#include
#include

int main(void)
{
char *buffer;
buffer = strerror(errno);
printf("Error: %s\n", buffer);
return 0;
}

11.函数名: strcmpi
功 能: 将一个串与另一个比较, 不管大小写
用 法: int strcmpi(char *str1, char *str2);
程序例:

#include
#include

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = strcmpi(buf2, buf1);

if (ptr > 0)
printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
printf("buffer 2 equals buffer 1\n");

return 0;
}