C non-block read from stdion

non-block-read-from-stdin.c

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <memory.h>
 
#define WSC_ATTACH_STDIN_BUFFER_SIZE 1024

int main()
{
	char wsc_attach_stdin_buffer[WSC_ATTACH_STDIN_BUFFER_SIZE] = {0};
	
#if 1
	int flag;
	flag = fcntl(STDIN_FILENO, F_GETFL);
	flag |= O_NONBLOCK;
	fcntl(STDIN_FILENO, F_SETFL, flag);
#endif
 
	while(1)
	{
        	if (strlen(wsc_attach_stdin_buffer) != 0) {
            		printf("%s", wsc_attach_stdin_buffer);
            		memset(wsc_attach_stdin_buffer, 0, sizeof(wsc_attach_stdin_buffer));
        	}

		fgets(wsc_attach_stdin_buffer,sizeof(wsc_attach_stdin_buffer) -1,stdin);
		sleep(1);
	}
}