Question

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define NAMELEN 50
#define MAXRECORD 500

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;

void read(char* filename, People *people) {
    FILE* fp=fopen(filename,"r");
    int i=0;    //data[i]
    char ilk[NAMELEN]="";   //Name
    char son[NAMELEN]="";   //Surname
    char str[256]="";   //To strtok function.
    char *token;    //To strtok function.

    people->size=0;
    people->data[i].numbers=malloc(sizeof(struct record_s));
    people->data[i].numbers->next=NULL;

    while(fgets(str,256,fp)!=NULL){
        token=strtok(str," ");
        people->data[i].id=atoi(token);
        token=strtok(str," ");
        strcpy(ilk,token);
        token=strtok(str," ");
        strcpy(son,token);
        token=strtok(str," ");
        people->data[i].expenditure=atof(token);
        strcat(ilk," ");
        strcat(ilk,son);
        strcpy(people->data[i].name,ilk);

        token=strtok(str," ");
            people->data[i].numbers->id=people->data[i].id;
        strcpy(people->data[i].numbers->number,token);
        token=strtok(str," ");

        while(token!=NULL){
            people->data[i].numbers->next=malloc(sizeof(struct record_s));
            people->data[i].numbers->next->next=NULL;
            people->data[i].numbers=people->data[i].numbers->next;

            people->data[i].numbers->id=people->data[i].id;
            strcpy(people->data[i].numbers->number,token);
            token=strtok(str," ");

        }

        i++;
        (people->size)++;
    }

    fclose(fp);
}

void print(People people) {
    int i,found = 0;
    Record *rec;
    /* header */
    printf("%-5s %-30s %-20s %-20s\n", "ID","NAME","EXPENDITURE","NUMBER(s)");
    /* line */
    for (i = 0; i < 78; ++i)
    printf("-");
    printf("\n");

    for (i = 0; i < people.size; ++i) {
        found = 0;
        printf("%-5d %-30s %-20.4f", people.data[i].id, people.data[i].name,         people.data[i].expenditure);
        rec = people.data[i].numbers;
        while(rec) {
            if(found)
                printf("%57s", "");
            else
                found = 1;
            printf("%-20s\n", rec->number);
            rec = rec->next;
        }
        printf("\n");
    }
}


int main(int argc, char** argv) {
    People people1,people2;
    people1.size = 0;
    read(argv[1],&people1);
    print(people1);
    return 0;
}

我得到核心dum所以试着看看gdb，这就出现了：

Program received signal SIGSEGV, Segmentation fault. _IO fgets (buf=0x7fffffff 5150 "", n=256, fp=0x0) at iofgets.c:50 50 iofgets.c: No such file or directory.

我不知道为什么我会遇到错误。

我的文字档案：

123 Asaf Avidan 25.2 05411975476 02224759866
221 Goksel Baktagir 12.4 03127586632
122 Goran Bregovic 10 02167418632
101 Marjan Farsad 27.8 05558741937 0555279431
36 Mark Eliyahu 36.6 05412147596 05423214587 05335841937
27 Mohsen Namjoo -1 05421458698 05447851489
192 Erkan Ogur 49.5 02162547896 02125847596 05325874586 05335412586

我正在尝试阅读ıd，名称，浮动和电话号码，我不知道哪个人有多少，所以我使用fgets（）函数逐行读取文本文件并打破我从fgets获取的字符串通过strtok（）fucntion进入令牌。

Answer 1

fopen()可能会失败。然后它返回NULL，尝试从NULL读取fgets()阻塞。

此

fgets (buf=0x7fffffff 5150 "", n=256, fp=0x0)

告诉您0已作为文件指针的值传递给“read”。 NULL最常见的是[{1}}。

您希望为可能失败的所有功能添加错误检查。

你可以这样做：

我正在努力解决C

1 个答案: