程序开头要声明#include <string.h>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("%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 <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("%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 <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: %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 <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; }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 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 <stdio.h>#include <string.h>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 <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 %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 <stdio.h>#include <string.h>#include <alloc.h>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 <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 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 <stdio.h>#include <errno.h>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 <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 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 <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 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 <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 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 <stdio.h>#include <string.h>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 <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 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 <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;}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: %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 <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: %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 <string.h>#include <stdio.h>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 <stdio.h>#include <string.h>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 <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 %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 <stdio.h>#include <string.h>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 <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 %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 <string.h>#include <stdio.h>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 <stdlib.h>#include <stdio.h>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 <stdio.h>#include <string.h>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 <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: %s\n", target); return 0;}
原文链接：http://www.byvoid.com/blog/c-string
