poll函数用法可以man一下。这里提供一个可以运行的示例。
  程序流程:
  父进程启动并创建子进程
  子进程通过管道发送数据给父进程
  父进程同时监听管道数据和shell输入,阻塞500毫秒发现没有数据打印一个"Testing...."
  父进程等待子进程结束
  子进程结束,父进程结束
  Ubuntu10.04:
  poll.cpp源代码:
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>// waitpid
#include <sys/types.h>// waitpid
#include <string.h>// strlen
#include <poll.h>// poll
/*
comment:
pipe is used between two processes on the same computer.
*/
#define TIMES 50
int main(){
int pipefds[2];
if( -1 == pipe( pipefds)){
printf( "Error when create pipes ");
}else{
int i;
pid_t pid = fork();
if( 0 == pid){// child
printf( "child running ");
close( pipefds[0]);
for( i = 0; i < TIMES; ++ i){
write( pipefds[1], "iamagoodguy", strlen( "iamagoodguy"));
sleep( 1);
}
}else{
printf( "parent running ");
char buf[256];
close( pipefds[1]);
struct pollfd pf[2];// key structure
pf[0].fd = 0;// console input
pf[0].events = POLLIN;// wait for bytes input
pf[1].fd = pipefds[0];// pipe input
pf[1].events = POLLIN;// wait for bytes input
for( i = 0; i < TIMES; ++ i){
poll( pf, 2, 500);// wait for only 500 ms
printf( "Testing... ");
if( pf[1].revents & POLLIN){
buf[ read( pipefds[0], buf, 256)] = '';
printf( "Receive:%s ", buf);
}
if( pf[0].revents & POLLIN){
buf[ read( 0, buf, 256)] = '';
printf( "Print:%s ", buf);
}
}
int status;
wait( & status);
}
}
return 0;
}