取文本文件第二列數的C程序

給有需要的同學借鑑一下，也爲了以後自己查找更方便

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

int main()
{
    FILE *fileIn, *fileOut;
    char inputFile[] = "100.txt";
    char outputFile[] = "200.txt";
    char inputLine[100];
    char *secondColumn;

    fileIn = fopen(inputFile, "r");

    if (fileIn == NULL)
    {
        printf("Error opening input file: %s! \n", inputFile);
        exit(-1);
    }

    fileOut = fopen(outputFile, "w");
    if (fileOut == NULL)
    {
        printf("Error opening output file: %s! \n", outputFile);    
        exit(1);
    }

    while (fgets(inputLine, 100, fileIn) != NULL)
    {
        strtok(inputLine, "\t");    
        secondColumn = strtok(NULL, "\t");
        int data = strtod(secondColumn, NULL);
        fprintf(fileOut, "%d\n", data);
    }
    fclose(fileIn);
    fclose(fileOut);

}