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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
函数名:
strncmp
功 能: 串比较
用 法: int strncmp(char *str1,
char *str2, int maxlen);
程序例:
#include
#include
int main(void)
{
char *buf1 =
“aaabbb”, *buf2 = “bbbccc”, *buf3 = “ccc”;
int
ptr;
ptr = strncmp(buf2,buf1,3);
if (ptr
> 0)
printf(“buffer 2 is greater than buffer 1\n”);
else
printf(“buffer 2 is less than buffer 1\n”);
ptr = strncmp(buf2,buf3,3);
if (ptr
> 0)
printf(“buffer 2 is greater than buffer 3\n”);
else
printf(“buffer 2 is less than buffer 3\n”);
return(0);
}
函数名:
strncmpi
功 能: 把串中的一部分与另一串中的一部分比较,
不管大小写
用 法: int strncmpi(char *str1,
char *str2);
程序例:
#include
#include
int
main(void)
{
char *buf1 =
“BBBccc”, *buf2 = “bbbccc”;
int
ptr;
ptr = strncmpi(buf2,buf1,3);
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;
}
函数名:
strncpy
功 能: 串拷贝
用 法: char *strncpy(char
*destin, char *source, int maxlen);
程序例:
#include
#include
int
main(void)
{
char
string[10];
char *str1 =
“abcdefghi”;
strncpy(string, str1, 3);
string[3] =
‘\0’;
printf(“%s\n”, string);
return
0;
}
函数名:
strnicmp
功 能: 不注重大小写地比较两个串
用 法: int strnicmp(char *str1,
char *str2, unsigned maxlen);
程序例:
#include
#include
int
main(void)
{
char *buf1 =
“BBBccc”, *buf2 = “bbbccc”;
int
ptr;
ptr = strnicmp(buf2, buf1, 3);
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;
}
函数名:
strnset
功 能: 将一个串中的所有字符都设为指定字符
用 法: char *strnset(char *str,
char ch, unsigned n);
程序例:
#include
#include
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;
}
函数名:
strpbrk
功 能: 在串中查找给定字符集中的字符
用 法: char *strpbrk(char *str1,
char *str2);
程序例:
#include
#include
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;
}
函数名:
strrchr
功 能: 在串中查找指定字符的最后一个出现
用 法: char *strrchr(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 =
strrchr(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;
}
函数名:
strrev
功 能: 串倒转
用 法: char *strrev(char
*str);
程序例:
#include
#include
int
main(void)
{
char
*forward = “string”;
printf(“Before strrev(): %s\n”, forward);
strrev(forward);
printf(“After strrev(): %s\n”,
forward);
return
0;
}
函数名:
strset
功 能: 将一个串中的所有字符都设为指定字符
用 法: char *strset(char *str,
char c);
程序例:
#include
#include
int
main(void)
{
char
string[10] = “123456789”;
char symbol
= ‘c’;
printf(“Before strset(): %s\n”, string);
strset(string, symbol);
printf(“After strset(): %s\n”,
string);
return
0;
}
函数名:
strspn
功 能: 在串中查找指定字符集的子集的第一次出现
用 法: int strspn(char *str1,
char *str2);
程序例:
#include
#include
#include
int
main(void)
{
char
*string1 = “1234567890”;
char
*string2 = “123DC8”;
int
length;
length = strspn(string1, string2);
printf(“Character where strings differ is at position %d\n”,
length);
return
0;
}
函数名:
strstr
功 能: 在串中查找指定字符串的第一次出现
用 法: char *strstr(char *str1,
char *str2);
程序例:
#include
#include
int
main(void)
{
char *str1 =
“Borland International”, *str2 = “nation”, *ptr;
ptr = strstr(str1, str2);
printf(“The
substring is: %s\n”, ptr);
return
0;
}
函数名:
strtod
功 能: 将字符串转换为double型值
用 法: double strtod(char *str,
char **endptr);
程序例:
#include
#include
int
main(void)
{
char
input[80], *endptr;
double
value;
printf(“Enter a floating point number:”);
gets(input);
value =
strtod(input, &endptr);
printf(“The
string is %s the number is %lf\n”, input, value);
return
0;
}
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: char *strtok(char *str1,
char *str2);
程序例:
#include
#include
int
main(void)
{
char
input[16] = “abc,d”;
char
*p;
p =
strtok(input, “,”);
if
(p) printf(“%s\n”, p);
p =
strtok(NULL, “,”);
if
(p) printf(“%s\n”, p);
return
0;
}
函数名:
strtol
功 能: 将串转换为长整数
用 法: long strtol(char *str,
char **endptr, int base);
程序例:
#include
#include
int
main(void)
{
char *string
= “87654321”, *endptr;
long
lnumber;
lnumber =
strtol(string, &endptr, 10);
printf(“string = %s long =
%ld\n”, string, lnumber);
return 0;
}
函数名:
strupr
功 能: 将串中的小写字母转换为大写字母
用 法: char *strupr(char
*str);
程序例:
#include
#include
int
main(void)
{
char *string
= “abcdefghijklmnopqrstuvwxyz”, *ptr;
ptr =
strupr(string);
printf(“%s\n”, ptr);
return
0;
}
函数名:
swab
功 能: 交换字节
用 法: void swab (char *from,
char *to, int nbytes);
程序例:
#include
#include
#include
char
source[15] = “rFna koBlrna d”;
char target[15];
int
main(void)
{
swab(source,
target, strlen(source));
printf(“This
is target: %s\n”, target);
return
0;
}