c - 尝试从读取的文件中 fprintf 某个字符串

Question

我正在努力将字符串从文件打印到新文件，但似乎无法集中注意力也无法让它工作，任何帮助都会很棒。

该文件如下所示:

New York,4:20,3:03Kansas City,12:03,3:00North Bay,16:00,0:20Kapuskasing,10:00,4:02Thunder Bay,0:32,0:31

I am trying to fprintf just the file names to a new file called theCities.txt. The logic makes sense in my head but in terms of implementation, I don't know how I can fprintf a pointer to the string. Any help would be great.

while (fgets(flightInfo[i], 1024, fp) > 0) {
    clearTrailingCarraigeReturn(flightInfo[i]);
    // display the line we got from the fill
    printf("  >>> read record [%s]\n", flightInfo[i]);

    char *p = flightInfo[i];
    for (;;) {
        p = strchr(p, ',');
        fp = fopen("theCities.txt", "w+");
        fprintf(fp, "%s\n", p);
        if (!p)
            break;
        ++p;
    }
    i++;
}

Answer 1

您处理文件指针的方式有误:

FILE *fpIn, *fpOut;
if (!(fpIn= fopen("yourfile.txt", "r"))) return -1;
if (!(fpOut=fopen("cities.txt", "w"))){fclose(fpIn); return -1;}
while (fgets(flightInfo[i], 1024, fpIn) > 0)
{
    clearTrailingCarraigeReturn(flightInfo[i]);
    // display the line we got from the fill
    printf("  >>> read record [%s]\n", flightInfo[i]);

    char *p = flightInfo[i];
    for (;;)
    {
        p = strchr(p, ',');
        fprintf(fpOut, "%s\n", p);
        if (!p) break;
        ++p;
    }

    i++;

}
fclose(fpIn);
fclose(fpOut);