在C中写入文件和控制台

Question

我正在尝试编写一个允许我写入控制台和C文件的函数.

我有以下代码,但我意识到它不允许我附加参数(如printf).

#include <stdio.h>

int footprint (FILE *outfile, char inarray[]) {
    printf("%s", inarray[]);
    fprintf(outfile, "%s", inarray[]);
}

int main (int argc, char *argv[]) {

    FILE *outfile;
    char *mode = "a+";
    char outputFilename[] = "/tmp/footprint.log";
    outfile = fopen(outputFilename, mode);

    char bigfoot[] = "It Smells!\n";
    int howbad = 10;

    footprint(outfile, "\n--------\n");

    /* then i realized that i can't send the arguments to fn:footprints */
    footprint(outfile, "%s %i",bigfoot, howbad); /* error here! I can't send bigfoot and howbad*/

    return 0;
}

我被困在这里 有小费吗？对于我想要发送到函数的参数:footprints,它将包含字符串,字符和整数.

是否有其他printf或fprintf fns,我可以尝试创建一个包装？

谢谢,希望听到你们的回复.

Answer 1

您可以使用<stdarg.h>功能vprintf和vfprintf.例如

void footprint (FILE * restrict outfile, const char * restrict format, ...) {

    va_list ap1, ap2;

    va_start(ap1, format);
    va_copy(ap2, ap1);

    vprintf(format, ap1);
    vfprintf(outfile, format, ap2);

    va_end(ap2);
    va_end(ap1);
}