user-0 提问: C语言分割字符串strtok和strsep

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user: user-0
content: 感谢楼上两位的指导，收获很大。 谢谢。

user: user-1
content: 仅供参考：#include <stdio.h> #include <string.h> char string[80]; char seps1[3]; char seps2[3]; char *token; char *zzstrtok (     char *string,     const char *control1,//连续出现时视为中间夹空token     const char *control2 //连续出现时视为中间无空token     ) {     unsigned char *str;     const unsigned char *ctrl1 = (const unsigned char *)control1;     const unsigned char *ctrl2 = (const unsigned char *)control2;     unsigned char map1[32],map2[32];     static char *nextoken;     static char flag=0;     unsigned char c;     int L;      memset(map1,0,32);     memset(map2,0,32);     do {         map1[*ctrl1 >> 3] |= (1 << (*ctrl1 & 7));     } while (*ctrl1++);     do {         map2[*ctrl2 >> 3] |= (1 << (*ctrl2 & 7));     } while (*ctrl2++);      if (string) {         if (control2[0]) {             L=strlen(string);             while (1) {                 c=string[L-1];                 if (map2[c >> 3] & (1 << (c & 7))) {                     L--;                     string[L]=0;                 } else break;             }         }         if (control1[0]) {             L=strlen(string);             c=string[L-1];             if (map1[c >> 3] & (1 << (c & 7))) {                 string[L]=control1[0];                 string[L+1]=0;             }         }         str=(unsigned char *)string;     }     else str=(unsigned char *)nextoken;      string=(char *)str;     while (1) {         if (0==flag) {             if (!*str) break;             if (map1[*str >> 3] & (1 << (*str & 7))) {                 *str=0;                 str++;                 break;             } else if (map2[*str >> 3] & (1 << (*str & 7))) {                 string++;                 str++;             } else {                 flag=1;                 str++;             }         } else if (1==flag) {             if (!*str) break;             if (map1[*str >> 3] & (1 << (*str & 7))) {                 *str=0;                 str++;                 flag=0;                 break;             } else if (map2[*str >> 3] & (1 << (*str & 7))) {                 *str=0;                 str++;                 flag=2;                 break;             } else str++;         } else {//2==flag             if (!*str) return NULL;             if (map1[*str >> 3] & (1 << (*str & 7))) {                 str++;                 string=(char *)str;                 flag=0;             } else if (map2[*str >> 3] & (1 << (*str & 7))) {                 str++;                 string=(char *)str;             } else {                 string=(char *)str;                 str++;                 flag=1;             }         }     }     nextoken=(char *)str;      if (string==(char *)str) return NULL;     else                     return string; } void main() {     strcpy(string,"A \tstring\t\tof ,,tokens\n\nand some  more tokens, ");     strcpy(seps1,",\n");strcpy(seps2," \t");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"1234| LIYI|China | 010 |201110260000|OK");     strcpy(seps1,"|");strcpy(seps2," ");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"1234|LIYI||010|201110260000|OK");     strcpy(seps1,"");strcpy(seps2,"|");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"1234|LIYI||010|201110260000|OK");     strcpy(seps1,"|");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"a");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"a,b");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"a,,b");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",a");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,"a,");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",a,,b");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",,a,,b,,");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",,");     strcpy(seps1,",");strcpy(seps2,"");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     }      strcpy(string,",,,");     strcpy(seps1,",");strcpy(seps2," ");     printf("\n[%s]\nTokens:\n",string);     token=zzstrtok(string,seps1,seps2);     while (token!=NULL) {         printf(" <%s>",token);         token=zzstrtok(NULL,seps1,seps2);     } } // //[A      string          of ,,tokens // //and some  more tokens, ] //Tokens: // <A> <string> <of> <> <tokens> <> <and> <some> <more> <tokens> <> //[1234| LIYI|China | 010 |201110260000|OK] //Tokens: // <1234> <LIYI> <China> <010> <201110260000> <OK> //[1234|LIYI||010|201110260000|OK] //Tokens: // <1234> <LIYI> <010> <201110260000> <OK> //[1234|LIYI||010|201110260000|OK] //Tokens: // <1234> <LIYI> <> <010> <201110260000> <OK> //[a] //Tokens: // <a> //[a,b] //Tokens: // <a> <b> //[a,,b] //Tokens: // <a> <> <b> //[,a] //Tokens: // <> <a> //[a,] //Tokens: // <a> <> //[,a,,b] //Tokens: // <> <a> <> <b> //[,,a,,b,,] //Tokens: // <> <> <a> <> <b> <> <> //[,] //Tokens: // <> <> //[,,] //Tokens: // <> <> <> //[,,,] //Tokens: // <> <> <> <>

user: user-2
content: strdup返回是malloc的首地址，因此str会跟着变化，但是str_bak会保存的malloc的首地址，这样free(str_bak);就不会有问题。free的参数是malloc返回的值（地址值）；     引用 1 楼 自信男孩 的回复:#include <stdio.h> #include <stdlib.h> #include <string.h>  int main(int arg, const char *argv[]) {     //char* string = strdup( "aaa#test#test#");          /*字符串不能为常量，所以strdup*/     char *str,  *str_bak;     char* p;      str = str_bak = strdup("aaa#test#test#");          /*字符串不能为常量，所以strdup*/      while((p = strsep(&str, "#")) != NULL)     {         printf("%s\n", p);     }      free(str_bak);      return 0;  }

user: user-2
content: #include <stdio.h> #include <stdlib.h> #include <string.h>  int main(int arg, const char *argv[]) {     //char* string = strdup( "aaa#test#test#");          /*字符串不能为常量，所以strdup*/     char *str,  *str_bak;     char* p;      str = str_bak = strdup("aaa#test#test#");          /*字符串不能为常量，所以strdup*/      while((p = strsep(&str, "#")) != NULL)     {         printf("%s\n", p);     }      free(str_bak);      return 0;  }