vprintf() 函数族 - 曲径通幽论坛

#include <stdio.h>
int vprintf(const char *format, va_list ap);
int vfprintf(FILE *stream, const char *format, va_list ap);

#include <stdarg.h>
#include <stdlib.h>

FILE *printer;
FILE *logfile;

int xprintf(const char *format, ...)
{
        va_list ap;
        va_start(ap, format);

        vprintf(format, ap);
        if(printer)
          vfprintf(printer, format, ap);
        if(logfile)
          vfprintf(logfile, format, ap);

        va_end(ap);
}
/*
int old_xprintf(const char *format, long a1, long a2, long a3, long a4,
                long a5, long a6, long a7, long a8)
{
        printf(format,a1, a2, a3, a4, a5, a6, a7, a8);
        if(printer)
          fprintf(printer, format, a1, a2, a3, a4, a5, a6, a7, a8);
        if(logfile)
          fprintf(logfile, format, a1, a2, a3, a4, a5, a6, a7, a8);

}
*/

int main(void)
{
        int a1 = 1, a2 = 2, a3 = 3, a4 = 4, a5 = 5, a6 = 6, a7 = 7, a8 = 8,
            a9 = 9;

        printer = fopen("test", "w+");
        logfile = fopen("test2", "w+");

//      old_xprintf("%d,%d,%d,%d,%d,%d,%d,%d\n", a1, a2, a3, a4, a5, a6, a7, a8);
        xprintf("kkkkkkk%d,%d,%d\n", a1, a2,a4,a5);

        fclose(printer);
        fclose(logfile);
        return 0;
}

beyes@linux-beyes:~/C/base> ./vsprintf.exe
kkkkkkk1,2,4
beyes@linux-beyes:~/C/base> cat test
kkkkkkk1,2,4
beyes@linux-beyes:~/C/base> cat test2
kkkkkkk1,2,4

beyes@linux-beyes:~/C/base> ./vsprintf.exe
kkkkkkk1,0,0