[转载]c++常用字符串操作函数

原文地址：c++常用字符串操作函数作者：Valsun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 <stdio.h>

#include <string.h>

int main(void)

{

char string[10];

char *str1 =
"abcdefghi";

stpcpy(string, str1);

printf("%sn", 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 <string.h>

#include <stdio.h>

int main(void)

{

char destination[25];

char *blank = " ", *c = "C++",
*Borland = "Borland";

strcpy(destination,
Borland);

strcat(destination,
blank);

strcat(destination, c);

printf("%sn",
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 <string.h>

#include <stdio.h>

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: %dn", c,
ptr-string);

else

printf("The character was not foundn");

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 <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 1n");

else

printf("buffer 2 is less than buffer 1n");

ptr =
strcmp(buf2, buf3);

if (ptr
> 0)

printf("buffer 2 is greater than buffer 3n");

else

printf("buffer 2 is less than buffer 3n");

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 <string.h>

#include <stdio.h>

int main(void)

{

char *buf1 = "BBB", *buf2 =
"bbb";

int ptr;

ptr = strcmpi(buf2,
buf1);

if (ptr >
0)

printf("buffer 2 is greater than buffer 1n");

if (ptr <
0)

printf("buffer 2 is less than buffer 1n");

if (ptr == 0)

printf("buffer 2 equals buffer 1n");

return 0;

}

函数名: strcpy

功 能: 串拷贝

用 法: char *strcpy(char *str1, char *str2);

程序例:

#include <stdio.h>

#include <string.h>

int main(void)

{

char
string[10];

char *str1 =
"abcdefghi";

strcpy(string, str1);

printf("%sn", 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 <stdio.h>

#include <string.h>

#include <alloc.h>

int main(void)

{

char
*string1 = "1234567890";

char
*string2 = "747DC8";

int
length;

length =
strcspn(string1, string2);

printf("Character where strings intersect is at position %dn",
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 <stdio.h>

#include <string.h>

#include <alloc.h>

int main(void)

{

char
*dup_str, *string = "abcde";

dup_str =
strdup(string);

printf("%sn", 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 <string.h>

#include <stdio.h>

int main(void)

{

char *buf1 = "BBB", *buf2 =
"bbb";

int ptr;

ptr = stricmp(buf2,
buf1);

if (ptr >
0)

printf("buffer 2 is greater than buffer 1n");

if (ptr <
0)

printf("buffer 2 is less than buffer 1n");

if (ptr == 0)

printf("buffer 2 equals buffer 1n");

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 <stdio.h>

#include <errno.h>

int main(void)

{

char *buffer;

buffer =
strerror(errno);

printf("Error: %sn",
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 <string.h>

#include <stdio.h>

int main(void)

{

char *buf1 = "BBB", *buf2 =
"bbb";

int ptr;

ptr = strcmpi(buf2,
buf1);

if (ptr >
0)

printf("buffer 2 is greater than buffer 1n");

if (ptr <
0)

printf("buffer 2 is less than buffer 1n");

if (ptr == 0)

printf("buffer 2 equals buffer 1n");

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 <string.h>

#include <stdio.h>

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 1n");

else

printf("buffer 2 is less than buffer 1n");

ptr =
strncmp(buf2,buf3,3);

if (ptr >
0)

printf("buffer 2 is greater than buffer 3n");

else

printf("buffer 2 is less than buffer 3n");

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 <string.h>

#include <stdio.h>

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 1n");

if (ptr <
0)

printf("buffer 2 is less than buffer 1n");

if (ptr == 0)

printf("buffer 2 equals buffer 1n");

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 <stdio.h>

#include <string.h>

int main(void)

{

char string[10];

char *str1 =
"abcdefghi";

strncpy(string, str1,
3);

string[3] = '';

printf("%sn", 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 <string.h>

#include <stdio.h>

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 1n");

if (ptr <
0)

printf("buffer 2 is less than buffer 1n");

if (ptr == 0)

printf("buffer 2 equals buffer 1n");

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 <stdio.h>

#include <string.h>

int main(void)

{

char *string =
"abcdefghijklmnopqrstuvwxyz";

char letter = 'x';

printf("string before strnset:
%sn", string);

strnset(string, letter,
13);

printf("string after strnset:
%sn", 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 <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: %cn", *ptr);

else

printf("strpbrk didn't find character in setn");

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 <string.h>

#include <stdio.h>

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: %dn", c,
ptr-string);

else

printf("The character was not foundn");

return 0;

}

函数名: strrev

功 能: 串倒转

用 法: char *strrev(char *str);

程序例:

#include <string.h>

#include <stdio.h>

int main(void)

{

char *forward =
"string";

printf("Before strrev():
%sn", forward);

strrev(forward);

printf("After strrev(): %sn",
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 <stdio.h>

#include <string.h>

int main(void)

{

char string[10] =
"123456789";

char symbol = 'c';

printf("Before strset():
%sn", string);

strset(string, symbol);

printf("After strset(): %sn",
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 <stdio.h>

#include <string.h>

#include <alloc.h>

int main(void)

{

char *string1 =
"1234567890";

char *string2 =
"123DC8";

int length;

length = strspn(string1,
string2);

printf("Character where
strings differ is at position %dn", 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 <stdio.h>

#include <string.h>

int main(void)

{

char *str1 = "Borland
International", *str2 = "nation", *ptr;

ptr = strstr(str1,
str2);

printf("The substring is:
%sn", 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 <stdio.h>

#include <stdlib.h>

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 %lfn", 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 <string.h>

#include <stdio.h>

int main(void)

{

char input[16] =
"abc,d";

char *p;

p = strtok(input, ",");

if
(p) printf("%sn", p);

p = strtok(NULL, ",");

if
(p) printf("%sn", 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 <stdlib.h>

#include <stdio.h>

int main(void)

{

char *string = "87654321",
*endptr;

long lnumber;

lnumber = strtol(string,
&endptr, 10);

printf("string = %s long =
%ldn", 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 <stdio.h>

#include <string.h>

int main(void)

{

char *string =
"abcdefghijklmnopqrstuvwxyz", *ptr;

ptr = strupr(string);

printf("%sn", 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 <stdlib.h>

#include <stdio.h>

#include <string.h>

char source[15] = "rFna koBlrna d";

char target[15];

int main(void)

{

swab(source, target,
strlen(source));

printf("This is target: %sn",
target);

return 0;

}