Question

我在C中做一个项目，我需要在.csv文件中搜索。但是，程序中存在一些错误，我无法找到它们。独立于我输入的城市（存在于文件中），唯一出现的是＆＃34; ERROR＆＃34;。有谁可以帮助我吗？谢谢！（对不起我的英语，这不是我的第一语言......）

int search_date(){
char tem_max[10];
char tem_min[10];
char humidity[10];
char pressure[10];
char town[100];
char city[100];
int i=0;

printf("Enter the name of the town: ");    
scanf ("%[^\n]%*c", town);

FILE *stream = fopen("cities2.csv", "r");

char line[1024];
    while (fgets(line, 1024, stream))
    {
        char *tmp = strdup(line);
        if (i > 0) {
            strcpy(city, strtok(tmp, ",\n"));  
            strcpy(tem_max, strtok(NULL, ","));  
            strcpy(tem_min, strtok(NULL, ","));
            strcpy(humidity, strtok(NULL, ","));
            strcpy(pressure, strtok(NULL, ","));

            if (strcmp(city, town) == 0)
            {
                printf("Town - Maximum temperature - Minimum temperature - Humidity - Pressure\n");
                printf("%s - %s - %s - %s - %s\n",city, tem_max, tem_min, humidity, pressure);
            }
        i++;      
        free(tmp);
        }
        else
        {
            printf("ERROR");
        }
    fclose(stream);
}

}

Answer 1

您将i初始化为0，然后在增加之前检查它是否大于0。看看你的代码，我真的不知道i的目的是什么。即使第一次测试通过，您所做的只是递增i并继续阅读。也许你试图跳过阅读文件的第一行？

int search_date(){
char tem_max[10];
char tem_min[10];
char humidity[10];
char pressure[10];
char town[100];
char city[100];
int i=0;                                             // <--- i is 0

printf("Enter the name of the town: ");    
scanf ("%[^\n]%*c", town);

FILE *stream = fopen("cities2.csv", "r");

char line[1024];
    while (fgets(line, 1024, stream))
    {
        char *tmp = strdup(line);
        if (i > 0) {                                // <--- i is still 0
            strcpy(city, strtok(tmp, ",\n"));  
            strcpy(tem_max, strtok(NULL, ","));  
            strcpy(tem_min, strtok(NULL, ","));
            strcpy(humidity, strtok(NULL, ","));
            strcpy(pressure, strtok(NULL, ","));

            if (strcmp(city, town) == 0)
            {
                printf("Town - Maximum temperature - Minimum temperature - Humidity - Pressure\n");
                printf("%s - %s - %s - %s - %s\n",city, tem_max, tem_min, humidity, pressure);
            }
        i++;                                      // <--- now you do i++
        free(tmp);
        }
        else
        {
            printf("ERROR");
        }
    fclose(stream);
}

Answer 2

嗨Stephen Docy是对的。他已经指出了你的错误。我刚刚修改了你的代码，以便它适合你。

int search_date(){
   char tem_max[10];
   char tem_min[10];
   char humidity[10];
   char pressure[10];
   char town[100];
   char city[100];
   int i=1;                                             // <--- now i is 1

   printf("Enter the name of the town: ");    
   scanf ("%[^\n]%*c", town);

   FILE *stream = fopen("cities2.csv", "r");

   char line[1024];
   while (fgets(line, 1024, stream))
   {
       char *tmp = strdup(line);
       if (i > 0) {                                // <--- i is now > 0
        strcpy(city, strtok(tmp, ",\n"));  
        strcpy(tem_max, strtok(NULL, ","));  
        strcpy(tem_min, strtok(NULL, ","));
        strcpy(humidity, strtok(NULL, ","));
        strcpy(pressure, strtok(NULL, ","));

        if (strcmp(city, town) == 0)
        {
            printf("Town - Maximum temperature - Minimum temperature - Humidity - Pressure\n");
            printf("%s - %s - %s - %s - %s\n",city, tem_max, tem_min, humidity, pressure);
        }
      i++;                                      // <--- now you do i++
      free(tmp);
    }
    else
    {
        printf("ERROR");
    }
  fclose(stream);
}

在C中的.csv文件中搜索

2 个答案: