C语言字符串函数大全(转自百度百科）
1 函数名: strcat 2 功 能: 字符串拼接函数 3 用 法: char *strcat(char *destin, char *source); 4 程序例: 5 #include <string.h> 6 #include <stdio.h> 7 int main(void) 8 { 9 char destination[25]; 10 char *blank = " ", *c = "C++", *Borland = "Borland"; 11 strcpy(destination, Borland); 12 strcat(destination, blank); 13 strcat(destination, c); 14 printf("%s\n", destination); 15 return 0; 16 } 17 18 19 20 函数名: strchr 21 功 能: 在一个串中查找给定字符的第一个匹配之处\ 22 用 法: char *strchr(char *str, char c); 23 程序例: 24 #include <string.h> 25 #include <stdio.h> 26 int main(void) 27 { 28 char string[15]; 29 char *ptr, c = 'r'; 30 strcpy(string, "This is a string"); 31 ptr = strchr(string, c); 32 if (ptr) 33 printf("The character %c is at position: %d\n", c, ptr-string); 34 else 35 printf("The character was not found\n"); 36 return 0; 37 } 38 39 40 41 函数名: strcmp 42 功 能: 串比较 43 用 法: int strcmp(char *str1, char *str2); 44 看Asic码，str1>str2，返回值 > 0；两串相等，返回0 45 程序例: 46 #include <string.h> 47 #include <stdio.h> 48 int main(void) 49 { 50 char *buf1 = "aaa", *buf2 = "bbb", *buf3 = "ccc"; 51 int ptr; 52 ptr = strcmp(buf2, buf1); 53 if (ptr > 0) 54 printf("buffer 2 is greater than buffer 1\n"); 55 else 56 printf("buffer 2 is less than buffer 1\n"); 57 ptr = strcmp(buf2, buf3); 58 if (ptr > 0) 59 printf("buffer 2 is greater than buffer 3\n"); 60 else 61 printf("buffer 2 is less than buffer 3\n"); 62 return 0; 63 } 64 65 66 67 函数名: strncmpi 68 功 能: 将一个串中的一部分与另一个串比较, 不管大小写 69 用 法: int strncmpi(char *str1, char *str2, unsigned maxlen); 70 程序例: 71 #include <string.h> 72 #include <stdio.h> 73 int main(void) 74 { 75 char *buf1 = "BBB", *buf2 = "bbb"; 76 int ptr; 77 ptr = strcmpi(buf2, buf1); 78 if (ptr > 0) 79 printf("buffer 2 is greater than buffer 1\n"); 80 if (ptr < 0) 81 printf("buffer 2 is less than buffer 1\n"); 82 if (ptr == 0) 83 printf("buffer 2 equals buffer 1\n"); 84 return 0; 85 } 86 87 88 89 函数名: strcpy 90 功 能: 串拷贝 91 用 法: char *strcpy(char *str1, char *str2); 92 程序例: 93 #include <stdio.h> 94 #include <string.h> 95 int main(void) 96 { 97 char string[10]; 98 char *str1 = "abcdefghi"; 99 strcpy(string, str1); 100 printf("%s\n", string); 101 return 0; 102 } 103 104 105 106 函数名: strcspn 107 功 能: 在串中查找第一个给定字符集内容的段 108 用 法: int strcspn(char *str1, char *str2); 109 程序例: 110 #include <stdio.h> 111 #include <string.h> 112 #include <alloc.h> 113 int main(void) 114 { 115 char *string1 = "1234567890"; 116 char *string2 = "747DC8"; 117 int length; 118 length = strcspn(string1, string2); 119 printf("Character where strings intersect is at position %d\n", length); 120 return 0; 121 } 122 123 124 125 函数名: strdup 126 功 能: 将串拷贝到新建的位置处 127 用 法: char *strdup(char *str); 128 程序例: 129 #include <stdio.h> 130 #include <string.h> 131 #include <alloc.h> 132 int main(void) 133 { 134 char *dup_str, *string = "abcde"; 135 dup_str = strdup(string); 136 printf("%s\n", dup_str); 137 free(dup_str); 138 return 0; 139 } 140 141 142 143 函数名: stricmp 144 功 能: 以大小写不敏感方式比较两个串 145 用 法: int stricmp(char *str1, char *str2); 146 程序例: 147 #include <string.h> 148 #include <stdio.h> 149 int main(void) 150 { 151 char *buf1 = "BBB", *buf2 = "bbb"; 152 int ptr; 153 ptr = stricmp(buf2, buf1); 154 if (ptr > 0) 155 printf("buffer 2 is greater than buffer 1\n"); 156 if (ptr < 0) 157 printf("buffer 2 is less than buffer 1\n"); 158 if (ptr == 0) 159 printf("buffer 2 equals buffer 1\n"); 160 return 0; 161 } 162 163 164 函数名: strerror 165 功 能: 返回指向错误信息字符串的指针 166 用 法: char *strerror(int errnum); 167 程序例: 168 #include <stdio.h> 169 #include <errno.h> 170 int main(void) 171 { 172 char *buffer; 173 buffer = strerror(errno); 174 printf("Error: %s\n", buffer); 175 return 0; 176 } 177 178 179 180 函数名: strcmpi 181 功 能: 将一个串与另一个比较, 不管大小写 182 用 法: int strcmpi(char *str1, char *str2); 183 程序例: 184 #include <string.h> 185 #include <stdio.h> 186 int main(void) 187 { 188 char *buf1 = "BBB", *buf2 = "bbb"; 189 int ptr; 190 ptr = strcmpi(buf2, buf1); 191 if (ptr > 0) 192 printf("buffer 2 is greater than buffer 1\n"); 193 if (ptr < 0) 194 printf("buffer 2 is less than buffer 1\n"); 195 if (ptr == 0) 196 printf("buffer 2 equals buffer 1\n"); 197 return 0; 198 } 199 200 201 202 函数名: strncmp 203 功 能: 串比较 204 用 法: int strncmp(char *str1, char *str2, int maxlen); 205 程序例: 206 #include <string.h> 207 #include <stdio.h> 208 int main(void) 209 { 210 char *buf1 = "aaabbb", *buf2 = "bbbccc", *buf3 = "ccc"; 211 int ptr; 212 ptr = strncmp(buf2,buf1,3); 213 if (ptr > 0) 214 printf("buffer 2 is greater than buffer 1\n"); 215 else 216 printf("buffer 2 is less than buffer 1\n"); 217 ptr = strncmp(buf2,buf3,3); 218 if (ptr > 0) 219 printf("buffer 2 is greater than buffer 3\n"); 220 else 221 printf("buffer 2 is less than buffer 3\n"); 222 return(0); 223 } 224 225 226 函数名: strncmpi 227 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 228 用 法: int strncmpi(char *str1, char *str2); 229 程序例: 230 #include <string.h> 231 #include <stdio.h> 232 int main(void) 233 { 234 char *buf1 = "BBBccc", *buf2 = "bbbccc"; 235 int ptr; 236 ptr = strncmpi(buf2,buf1,3); 237 if (ptr > 0) 238 printf("buffer 2 is greater than buffer 1\n"); 239 if (ptr < 0) 240 printf("buffer 2 is less than buffer 1\n"); 241 if (ptr == 0) 242 printf("buffer 2 equals buffer 1\n"); 243 return 0; 244 } 245 246 247 函数名: strncpy 248 功 能: 串拷贝 249 用 法: char *strncpy(char *destin, char *source, int maxlen); 250 程序例: 251 #include <stdio.h> 252 #include <string.h> 253 int main(void) 254 { 255 char string[10]; 256 char *str1 = "abcdefghi"; 257 strncpy(string, str1, 3); 258 string[3] = '\0'; 259 printf("%s\n", string); 260 return 0; 261 } 262 263 264 函数名: strnicmp 265 功 能: 不注重大小写地比较两个串 266 用 法: int strnicmp(char *str1, char *str2, unsigned maxlen); 267 程序例: 268 #include <string.h> 269 #include <stdio.h> 270 int main(void) 271 { 272 char *buf1 = "BBBccc", *buf2 = "bbbccc"; 273 int ptr; 274 ptr = strnicmp(buf2, buf1, 3); 275 if (ptr > 0) 276 printf("buffer 2 is greater than buffer 1\n"); 277 if (ptr < 0) 278 printf("buffer 2 is less than buffer 1\n"); 279 if (ptr == 0) 280 printf("buffer 2 equals buffer 1\n"); 281 return 0; 282 } 283 284 285 286 函数名: strnset 287 功 能: 将一个串中的所有字符都设为指定字符 288 用 法: char *strnset(char *str, char ch, unsigned n); 289 程序例: 290 #include <stdio.h> 291 #include <string.h> 292 int main(void) 293 { 294 char *string = "abcdefghijklmnopqrstuvwxyz"; 295 char letter = 'x'; 296 printf("string before strnset: %s\n", string); 297 strnset(string, letter, 13); 298 printf("string after strnset: %s\n", string); 299 return 0; 300 } 301 302 303 函数名: strpbrk 304 功 能: 在串中查找给定字符集中的字符 305 用 法: char *strpbrk(char *str1, char *str2); 306 程序例: 307 #include <stdio.h> 308 #include <string.h> 309 int main(void) 310 { 311 char *string1 = "abcdefghijklmnopqrstuvwxyz"; 312 char *string2 = "onm"; 313 char *ptr; 314 ptr = strpbrk(string1, string2); 315 if (ptr) 316 printf("strpbrk found first character: %c\n", *ptr); 317 else 318 printf("strpbrk didn't find character in set\n"); 319 return 0; 320 } 321 322 323 324 函数名: strrchr 325 功 能: 在串中查找指定字符的最后一个出现 326 用 法: char *strrchr(char *str, char c); 327 程序例: 328 #include <string.h> 329 #include <stdio.h> 330 int main(void) 331 { 332 char string[15]; 333 char *ptr, c = 'r'; 334 strcpy(string, "This is a string"); 335 ptr = strrchr(string, c); 336 if (ptr) 337 printf("The character %c is at position: %d\n", c, ptr-string); 338 else 339 printf("The character was not found\n"); 340 return 0; 341 } 342 343 344 345 函数名: strrev 346 功 能: 串倒转 347 用 法: char *strrev(char *str); 348 程序例: 349 #include <string.h> 350 #include <stdio.h> 351 int main(void) 352 { 353 char *forward = "string"; 354 printf("Before strrev(): %s\n", forward); 355 strrev(forward); 356 printf("After strrev(): %s\n", forward); 357 return 0; 358 } 359 360 函数名: strset 361 功 能: 将一个串中的所有字符都设为指定字符 362 用 法: char *strset(char *str, char c); 363 程序例: 364 #include <stdio.h> 365 #include <string.h> 366 int main(void) 367 { 368 char string[10] = "123456789"; 369 char symbol = 'c'; 370 printf("Before strset(): %s\n", string); 371 strset(string, symbol); 372 printf("After strset(): %s\n", string); 373 return 0; 374 } 375 376 377 378 函数名: strspn 379 功 能: 在串中查找指定字符集的子集的第一次出现 380 用 法: int strspn(char *str1, char *str2); 381 程序例: 382 #include <stdio.h> 383 #include <string.h> 384 #include <alloc.h> 385 int main(void) 386 { 387 char *string1 = "1234567890"; 388 char *string2 = "123DC8"; 389 int length; 390 length = strspn(string1, string2); 391 printf("Character where strings differ is at position %d\n", length); 392 return 0; 393 } 394 395 396 函数名: strstr 397 功 能: 在串中查找指定字符串的第一次出现 398 用 法: char *strstr(char *str1, char *str2); 399 程序例: 400 #include <stdio.h> 401 #include <string.h> 402 int main(void) 403 { 404 char *str1 = "Borland International", *str2 = "nation", *ptr; 405 ptr = strstr(str1, str2); 406 printf("The substring is: %s\n", ptr); 407 return 0; 408 } 409 410 411 函数名: strtod 412 功 能: 将字符串转换为double型值 413 用 法: double strtod(char *str, char **endptr); 414 程序例: 415 #include <stdio.h> 416 #include <stdlib.h> 417 int main(void) 418 { 419 char input[80], *endptr; 420 double value; 421 printf("Enter a floating point number:"); 422 gets(input); 423 value = strtod(input, &endptr); 424 printf("The string is %s the number is %lf\n", input, value); 425 return 0; 426 } 427 428 429 430 函数名: strtok 431 功 能: 查找由在第二个串中指定的分界符分隔开的单词 432 用 法: char *strtok(char *str1, char *str2); 433 程序例: 434 #include <string.h> 435 #include <stdio.h> 436 int main(void) 437 { 438 char input[16] = "abc,d"; 439 char *p; 440 /* strtok places a NULL terminator 441 in front of the token, if found */ 442 p = strtok(input, ","); 443 if (p) printf("%s\n", p); 444 /* A second call to strtok using a NULL 445 as the first parameter returns a pointer 446 to the character following the token */ 447 p = strtok(NULL, ","); 448 if (p) printf("%s\n", p); 449 return 0; 450 } 451 452 453 454 函数名: strtol 455 功 能: 将串转换为长整数 456 用 法: long strtol(char *str, char **endptr, int base); 457 程序例: 458 #include <stdlib.h> 459 #include <stdio.h> 460 int main(void) 461 { 462 char *string = "87654321", *endptr; 463 long lnumber; 464 /* strtol converts string to long integer */ 465 lnumber = strtol(string, &endptr, 10); 466 printf("string = %s long = %ld\n", string, lnumber); 467 return 0; 468 } 469 470 函数名: strupr 471 功 能: 将串中的小写字母转换为大写字母 472 用 法: char *strupr(char *str); 473 程序例: 474 #include <stdio.h> 475 #include <string.h> 476 int main(void) 477 { 478 char *string = "abcdefghijklmnopqrstuvwxyz", *ptr; 479 /* converts string to upper case characters */ 480 ptr = strupr(string); 481 printf("%s\n", ptr); 482 return 0; 483 } 484 485 486 487 函数名: swab 488 功 能: 交换字节 489 用 法: void swab (char *from, char *to, int nbytes); 490 程序例: 491 #include <stdlib.h> 492 #include <stdio.h> 493 #include <string.h> 494 char source[15] = "rFna koBlrna d"; 495 char target[15]; 496 int main(void) 497 { 498 swab(source, target, strlen(source)); 499 printf("This is target: %s\n", target); 500 return 0; 501 }
原文转自：http://www.cnblogs.com/shangyu/archive/2012/02/12/2347710.html
