C語言字符串函數(shù)集錦（二）
作者：佚名
本文介紹的是C語言中的字符串函數(shù)，每個函數(shù)都介紹了用法，并舉例介紹的。希望對大家有幫助，一起來看。
說起字符串函數(shù)，我想大家都不陌生。字符串函數(shù)對二進制數(shù)據(jù)、字符串和表達式執(zhí)行不同的運算。下面總結(jié)了C語言中的字符串函數(shù)。
13、函數(shù)名: strncmpi
功 能: 把串中的一部分與另一串中的一部分比較, 不管大小寫
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;
- }
14、函數(shù)名: strncpy
功 能: 串拷貝
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;
- }
15、函數(shù)名: strnicmp
功 能: 不注重大小寫地比較兩個串
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;
- }
16、函數(shù)名: strnset
功 能: 將一個串中的所有字符都設(shè)為指定字符
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;
- }
17、函數(shù)名: strpbrk
功 能: 在串中查找給定字符集中的字符
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;
- }
18、函數(shù)名: strrchr
功 能: 在串中查找指定字符的最后一個出現(xiàn)
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;
- }
19、函數(shù)名: strrev
功 能: 串倒轉(zhuǎn)
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;
- }
#p#
20、函數(shù)名: strset
功 能: 將一個串中的所有字符都設(shè)為指定字符
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;
- }
21、函數(shù)名: strspn
功 能: 在串中查找指定字符集的子集的第一次出現(xiàn)
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;
- }
22、函數(shù)名: strstr
功 能: 在串中查找指定字符串的第一次出現(xiàn)
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;
- }
23、函數(shù)名: strtod
功 能: 將字符串轉(zhuǎn)換為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;
- }
24、函數(shù)名: strtok
功 能: 查找由在第二個串中指定的分界符分隔開的單詞
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;
- /* strtok places a NULL terminator
- in front of the token, if found */
- p = strtok(input, ",");
- if (p) printf("%s\n", p);
- /* A second call to strtok using a NULL
- as the first parameter returns a pointer
- to the character following the token */
- p = strtok(NULL, ",");
- if (p) printf("%s\n", p);
- return 0;
- }
25、函數(shù)名: strtol
功 能: 將串轉(zhuǎn)換為長整數(shù)
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;
- /* strtol converts string to long integer */
- lnumber = strtol(string, &endptr, 10);
- printf("string = %s long = %ld\n", string, lnumber);
- return 0;
- }
26、函數(shù)名: strupr
功 能: 將串中的小寫字母轉(zhuǎn)換為大寫字母
用 法:
- char *strupr(char *str);
程序例:
- #include <stdio.h>
- #include <string.h>
- int main(void)
- {
- char *string = "abcdefghijklmnopqrstuvwxyz", *ptr;
- /* converts string to upper case characters */
- ptr = strupr(string);
- printf("%s\n", ptr);
- return 0;
- }
27、函數(shù)名: swab
功 能: 交換字節(jié)
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;
- }
到這，關(guān)于字符串函數(shù)的介紹就給大家介紹完了。希望對你有幫助。
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