扫描/打印第一行后代码崩溃

时间:2017-02-19 17:21:34

标签: c printing crash crash-reports

此代码在扫描并从数据库打印第一行后崩溃。我真的找不到任何解决办法。

坠机事件:

Crash

数据库的内容:

Matthew Summers 53901523 256325 135500
Jacob Sutherland 52392302 723232.2 1200000
Michael Phelps 58238211 971000.52 653350
Aaron Gordon 59923325 325700.92 623320
Vasil Maglaperidze 59952323 189900.32 330000
Avtandil Shoshiashvili 95234322 432000.72 723023
Michael Jordan 35252372 120899.75 50000
Daniel Whiteman 85238202 178500.53 349800
James Oneal 98773235 90750.23 197050
Haytheim Russels 19326233 178250.22 221580

我的代码:

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

#define CHAR_BUF 128
#define DATA_FILE "database.txt"

typedef struct client
{
    char fname[CHAR_BUF];
    char lname[CHAR_BUF];
    int pnumber;
    float wins;
    float loses;
    float ratio;
}client;

int ReadData(FILE *fp);

int main()
{
    //int lines=0;
    //client client[i];
    FILE *fp = fopen(DATA_FILE, "r"); // opens file
    if(fp==NULL) // checks if .txt file is empty
    {
        printf("Database is empty.");
        exit(1);
    }
    ReadData(fp); // Calls function to read db
    //lines = ReadData(fp);
    //printf("Line amount: %d", lines);
}


/* This function reads data from database
* and assigns values to their variables
*/
int ReadData(FILE *fp)
{
    int i=0;
    client client[i];
    while(!feof(fp))
    {
        fscanf(fp, "%s %s %d %f %f", client[i].fname, client[i].lname,
        &client[i].pnumber, &client[i].wins, &client[i].loses);
        printf("%s %s %d %.2f %.2f\n", client[i].fname, client[i].lname,
        client[i].pnumber, client[i].wins, client[i].loses);
        i++;
    }
    return i;
}

1 个答案:

答案 0 :(得分:0)

  1. int i=0;   
    client client[i];  
    

    这将创建一个大小为0的数组(这没有任何意义。)
    将其更改为:

    #define MAX 30
    
    client client[MAX];
    
  2. while(!feof(fp))  
    

    当从文件中读取最后一条记录时,最后仍然有\n。因此,当此表达式被评估时feof(fp)返回FALSE,因为它还不是文件的结尾。
    但在下一行fscanf(fp, "%s %s %d %f %f", client[i].fname, client[i].lname, &client[i].pnumber, &client[i].wins, &client[i].loses);eofscanf失败 这解释了最后一条垃圾线 解决方案:
    检查scanf是否成功,如果成功,则仅执行printf

    while(fscanf(fp, "%127s %127s %d %f %f", client[i].fname, client[i].lname, &client[i].pnumber, &client[i].wins, &client[i].loses) == 5)  
    {    
        printf("%s %s %d %.2f %.2f\n", client[i].fname, client[i].lname, client[i].pnumber, client[i].wins, client[i].loses);
        i++;
    }