sscanf（）未写入变量

Question

我正在从csv文件中读取数据，以便将其复制到数组中。数据格式为int1,String1,String2,String3,String4,int2我使用sscanf分隔这些参数。

此函数将文件指针和动态分配的数组作为参数，并将数据从文件复制到数组。我正在使用6个中间变量来保存读取的数据以检查其有效性。

//temporary variables for checks
        int  month = 0;
        char origin[4];
        char destination[4];
        char airline[4];
        char type[10]; //will only be used to parse the file
        int  passengerCount = 0;


/******************************************************************************************************/
    while(!feof(fileIn))
    {
        fgets(buffer, 1000, fileIn);
        if(buffer == NULL)
            continue;

        printf("\n%s", buffer); //Using this to check correct read

                sscanf(buffer,"%d,%[^,],%[^,],%[^,],%[^,],%d", &month, origin, destination, airline, type, &passengerCount);

        if (strlen(airline) > 2) //skips value if airline code is over 2 chars long
        {
            skipCount++;
            continue;
        }

        printf("Checks: %d,%s,%s,%s,%s,%d\n", month, origin, destination, airline, type, passengerCount); //using this to check correct read from buffer
/*******************************************************************************************************/

[运行时，这段代码应读取文件，检查airline是否长于2个字符，并跳过那些。由于某些原因，sscanf（）会正确写入所有变量，但airline始终为空。.csv文件中的前三行：

6,JFK,LHR,VS,Passengers,85790
6,JFK,CDG,AF,Passengers,85324
6,LGA,YYZ,AC,Passengers,82389

这是输出：

Buffer: 6,JFK,LHR,VS,Passengers,85790
Checks: 6,JFK,LHR,,Passengers,85790

Buffer: 6,JFK,CDG,AF,Passengers,85324
Checks: 6,JFK,CDG,,Passengers,85324

Buffer: 6,LGA,YYZ,AC,Passengers,82389
Checks: 6,LGA,YYZ,,Passengers,82389

Answer 1

我看到的问题是：在执行[[sscanf时，您具有以下内容：

sscanf(buffer,"Buffer: %d,%[^,],%[^,],%[^,],%[^,],%d", &month, origin, destination, airline, type, &passengerCount);

这里是示例解决方案：
#include <cstdio>      
int main(){
    //temporary variables for checks
    int  month = 0;
    char origin[4];
    char destination[4];
    char airline[4];
    char type[10]; //will only be used to parse the file
    int  passengerCount = 0;

    FILE *fileIn = fopen("sample.txt","r");
    char buffer[100];
    int skipCount = 0;
    while(!feof(fileIn))
    {
        if(fgets(buffer, 100, fileIn) == NULL)
            continue;
        printf("\n%s\n", buffer); //Using this to check correct read
            sscanf(buffer,"%d,%[^,],%[^,],%[^,],%[^,],%d", &month, origin, destination, airline, type, &passengerCount);

        if (strlen(airline) > 2) //skips value if airline code is not 2 chars long
        {
            skipCount++;
            continue;
        }
        printf("Checks: %d,%s,%s,%s,%s,%d\n", month, origin, destination, airline, type, passengerCount); //using this to check correct read from buffer
    }
}

我的sample.txt文件如下：
6,JFK,LHR,VS,Passengers,85790
6,JFK,CDG,AF,Passengers,85324
6,LGA,YYZ,AC,Passengers,82389

执行此命令时，我得到：
6,JFK,LHR,VS,Passengers,85790

Checks: 6,JFK,LHR,VS,Passengers,85790

6,JFK,CDG,AF,Passengers,85324

Checks: 6,JFK,CDG,AF,Passengers,85324

6,LGA,YYZ,AC,Passengers,82389
Checks: 6,LGA,YYZ,AC,Passengers,82389

[另外，我认为您应该在解析这样的字符串时使用strtok。它要干净得多。