Question

Strtok函数应该将字符串切成碎片。我用了＃34; ＆＃34;最初是delim和＆＃34; ，\ n＆＃34;切割字符串。问题是当它从strtok函数获取NULL时，它继续分配并且不会中断循环。因此它读取错误并为某些数据分配NULL。我认为问题是For循环内部的For循环，当它变为NULL时，它必须断开＆＃34; token＆＃34;但它没有。我怎么知道：我打印结构数据，它将NULL分配给最后一个字符串赋值，0分配给链接列表中最后一个元素的id。

所以很快它再工作一次，然后它应该是每次。虽然我试图将NULL指向当前它实际上并没有改变任何东西。还读了一次。

typedef struct record_s {
    int id;
    char number[NAMELEN];
    struct record_s *next;
} Record;

typedef struct person_s {
    int id;
    char name[NAMELEN];
    double expenditure;
    Record *numbers;
} Person;

typedef struct people_s {
    Person data[MAXRECORD];
    int size;
} People;

     for(i=0;i<satir;i++){ 
                current=(Record*)malloc(sizeof(Record));
                people1.data[i].numbers=current;                                            
                head=people1.data[i].numbers;

                fscanf(fp,"%d%s%s%lf",&people1.data[i].id,a,b,&people1.data[i].expenditure);
                fgets (str, 60, fp);

                token=strtok(str," ");
                ztemp=0;
                  while (token != NULL)
                    {
                        ptr=(Record*)malloc(sizeof(Record));
                        strcpy(numbers[z],token);
                        strcpy(current->number,numbers[z]);
                        current->id=people1.data[i].id;


                        token = strtok (NULL, " ,\n");
                        current->next=ptr;
                        current=ptr;
                        z++;
                        ztemp++;

                    }

                    current=NULL; 
                    people1.data[i].numbers=head;
                    test=head;
                    while(test!=NULL){
                        printf("%d is id, %s is supposedly the number\n",test->id,test->number);
                        test=test->next;
                    }
                   //printf("z is %d\n",ztemp); 

                strcat(a," ");
                strcat(a,b);
                strcpy(people1.data[i].name,a);


            }
            for(o=0;o<satir;o++){
                x=0;
                x=strcspn(numbers[o],"\n");
                if(x!=0)
                    numbers[i][o]='\0';
            }
    people1.size=i;
    fclose(fp);
    print(people1);
    return 0;
}

另外请指出，如果格式有任何问题而不是downvoting我会很快修复，我投票很少，谢谢。

Strtok函数返回NULL，但它不应该

0 个答案: