p10-8.c

来自「SUN Solaris8平台下进程间通信」· C语言 代码 · 共 34 行

#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <errno.h>
int input_timeout(int filedes, unsigned int seconds)
{
    fd_set set;
    struct timeval timeout;
    int n;
    char buf[1024];
    FD_ZERO(&set);             /* 初始文件描述字集合 */
    FD_SET(filedes, &set);
    timeout.tv_sec = seconds;  /* 初始timeout数据结构 */
    timeout.tv_usec = 0;
    /* select时间到期返回0；输入就绪返回1；出现错误返回-1 */
again:
    if ((n = select(FD_SETSIZE, &set, NULL, NULL, &timeout)) < 0) { 
        if (errno = EINTR) 
            goto again;
    }
    else if (n > 0) {
        n = read(filedes,buf,sizeof(buf));
        printf("read data:  %s\n",buf);
    }
    else
        printf("tiomeout for select\n");
    return n;
}
int main (void)
{
    fprintf(stderr, "select returned %d.\n",input_timeout(STDIN_FILENO, 5));
    return 0;
}