strcpy
函数名: strcpy功 能: 拷贝一个字符串到另一个用 法: char *strcpy(char *destin, char *source);程序例:#include #include int main(void){ char string[10];char *str1 = "abcdefghi";strcpy(string, str1);printf("%s\n", string);return 0;} strncpy
函数名:strncpy原型：char * strncpy(char *dest, char *src, size_t n); 功能：将字符串src中最多n个字符复制到字符数组dest中(它并不像strcpy一样遇到NULL才停止复制，而是等凑够n个字符才开始复制），返回指向dest的指针。#include #include int main(void){ char string[10];char *str1 = "abcdefghi";strncpy(string, str1,3);printf("%s\n", string);return 0;} strcat
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;} strchr
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);elseprintf("The character was not found\n");return 0;} strcmp
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");elseprintf("buffer 2 is less than buffer 1\n");ptr = strcmp(buf2, buf3);if (ptr > 0)printf("buffer 2 is greater than buffer 3\n");elseprintf("buffer 2 is less than buffer 3\n");return 0;} strnicmp
函数名: strnicmp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 strnicmp(char *str1, char *str2, unsigned maxlen);程序例:#include #include int main(void){ char *buf1 = "BBB", *buf2 = "bbb";int ptr;ptr = strnicmp(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;} strlen
函数名:strlen功能: strlen函数求的是字符串的长度，它求得方法是从字符串的首地址开始到遇到第一个'\0'停止计数,如果你只定义没有给它赋初值，这个结果是不定的，它会从字符串首地址一直记下去，直到遇到'\0'才会停止。原型: size_t strlen(const char *s);#include #include int main(){ int i=0;char *he ="Hello,world";i=strlen(he);printf("字符串长度为%d\n",i);return 0;} //运行结果：字符串长度为11 strcspn
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;} strdup
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;} stricmp
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;} strerror
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;} strcmpi
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;} strnicmp
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;} strnset
函数名: strnset功 能: 将一个字符串前n个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;} strpbrk
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);elseprintf("strpbrk didn't find character in set\n");return 0;} strrchr
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);elseprintf("The character was not found\n");return 0;} strrev
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;} strset
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;} strstr
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;} strtod
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;} strtok
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;/* strtok places a NULL terminatorin front of the token, if found */p = strtok(input, ",");if (p) printf("%s\n", p);/* A second call to strtok using a NULLas the first parameter returns a pointerto the character following the token */p = strtok(NULL, ",");if (p) printf("%s\n", p);return 0;} strtol
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;/* strtol converts string to long integer */lnumber = strtol(string, &endptr, 10);printf("string = %s long = %ld\n", string, lnumber);return 0;} strupr
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;//定义为数组才能修改/* converts string to upper case characters */ptr = strupr(string);printf("%s\n", ptr);return 0;} swab
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;} 以上都是些C中字符串的常用函数，非常实用，此处记录，方便以后温故:)