How to flush the stdin??
Why is it not working in the following code snippet?
#include <string.h>
#include <stdio.h>
#include <malloc.h>
#include <fcntl.h>
int main() {
int i = 0, j = 0, sat;
char arg[256];
char *argq;
argq = malloc(sizeof(char) * 10);
printf("Input the line\n");
i = read(0, arg, sizeof(char) * 9);
arg[i - 1] = '\0';
fflush(stdin);
i = read(0, argq, sizeof(char) * 5);
argq[i - 1] = '\0';
puts(arg);
puts(argq);
return 0;
}
Now if I give the input as 11 characters, only 9 should be read but the remaining two characters in the stdin are not flushed and read again in the argq. Why?
Input: 123 456 789
Output:
123 456
89
Why am I getting this 89
as the output?
I believe fflush is only used with output streams.
You might try fpurge or __fpurge on Linux. Note that fpurge is nonstandard and not portable. It may not be available to you.
From a Linux fpurge man page: Usually it is a mistake to want to discard input buffers.
The most portable solution for flushing stdin would probably be something along the lines of the following:
int c;
while ((c = getchar()) != '\n' && c != EOF);