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| #include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <sys/wait.h>
#include <sys/time.h>
void sig_alarm(int signo)
{
printf("catch SIGALRM in sleep_cmd\n");
}
void sig_real_alarm(int signo)
{
printf("catch real SIGALRM\n");
}
int system_cmd(const char *pCmd)
{
pid_t pid;
int status;
sigset_t newMask, oldMask;
struct sigaction currAction, oldAction;
if (pCmd == NULL)
{
return 1;
}
currAction.sa_handler = SIG_IGN;
currAction.sa_flags = 0;
sigemptyset(&currAction.sa_mask);
if (sigaction(SIGINT, &currAction, &oldAction) < 0)
{
return (-1);
}
if (sigaction(SIGQUIT,&currAction, &oldAction) < 0)
{
return (-1);
}
sigemptyset(&newMask);
sigemptyset(&oldMask);
sigaddset(&newMask, SIGCHLD);
if (sigprocmask(SIG_BLOCK, &newMask, &oldMask) < 0)
{
return (-1);
}
if ( (pid = fork()) < 0)
{
status = -1;
}
else if (pid == 0)
{
sigaction(SIGINT, &oldAction, NULL);
sigaction(SIGQUIT, &oldAction, NULL);
sigprocmask(SIG_SETMASK, &oldMask, NULL);
execl("/bin/bash", "sh", "-c", pCmd, (char*)0);
_exit(127);
}
else
{
while (waitpid(pid, &status, 0) < 0)
{
if (errno != EINTR)
{
status = -1;
break;
}
}
}
if (sigaction(SIGINT, &oldAction, NULL) < 0)
{
return (-1);
}
if (sigaction(SIGQUIT, &oldAction, NULL) < 0)
{
return (-1);
}
if (sigprocmask(SIG_SETMASK, &oldMask, NULL) < 0)
{
return (-1);
}
return (status);
}
//sleep_cmd未处理与以前设置的闹钟的交互作用, 现在的处理会使之前设置的闹钟失效
unsigned int sleep_cmd(unsigned int nsec)
{
sigset_t newMask, oldMask, suspendMask;
struct sigaction newAction, oldAction;
unsigned int uslept;
newAction.sa_handler = sig_alarm;
sigemptyset(&newAction.sa_mask);
newAction.sa_flags = 0;
if (sigaction(SIGALRM, &newAction, &oldAction) < 0)
{
printf("set SIGALRM new action error\n");
}
sigemptyset(&newMask);
sigaddset(&newMask, SIGALRM);
sigprocmask(SIG_BLOCK, &newMask, &oldMask);
alarm(nsec);
suspendMask = oldMask;
sigdelset(&suspendMask, SIGALRM); //不阻塞SIGALRM
sigsuspend(&suspendMask);
uslept = alarm(0);
if (sigaction(SIGALRM, &oldAction, NULL) < 0)
{
printf("set SIGALRM old Action error\n");
}
sigprocmask(SIG_SETMASK, &oldMask, NULL);
return uslept;
}
int main(int argc, char **argv)
{
int index = 1;
int cmdLen = 0;
unsigned int remainSec = 0;
char cmdBuff[1024] = {0};
//struct itimerval its;
struct itimerspec itms;
struct sigaction sigAction;
timer_t timerid;
struct sigevent sev;
if (argc <= 1)
{
printf("no cmd of argv\n");
return 0;
}
for (index = 1; index < argc; index++)
{
sprintf(cmdBuff + cmdLen, "%s ", argv[index]);
cmdLen += strlen(argv[index]) + 1;
}
cmdBuff[cmdLen] = '\0';
printf("%s\n", cmdBuff);
system_cmd(cmdBuff);
sigAction.sa_handler = sig_real_alarm;
sigemptyset(&sigAction.sa_mask);
sigAction.sa_flags = 0;
sigaction(SIGALRM, &sigAction, NULL);
/*
its.it_value.tv_sec = 1;
its.it_value.tv_usec = 0;
its.it_interval.tv_sec = 1;
its.it_interval.tv_usec = 0;
if (setitimer(ITIMER_REAL, &its, NULL))
{
printf("set timer error\n");
}*/
//setitimer 与 alarm共用一个定时器，互相干扰。
//创建定时器，发送的信号为SIGALRM
sev.sigev_notify = SIGEV_SIGNAL;
sev.sigev_signo = SIGALRM;
sev.sigev_value.sival_ptr = &timerid;
if (timer_create(CLOCK_REALTIME, &sev, &timerid) == -1)
{
printf("timer_create error\n");
}
itms.it_value.tv_sec = 1;
itms.it_value.tv_nsec = 0;
itms.it_interval.tv_sec = itms.it_value.tv_sec;
itms.it_interval.tv_nsec = itms.it_value.tv_nsec;
//设置定时器
if (timer_settime(timerid, 0, &itms, NULL) == -1)
{
printf("timer_settime error\n");
}
remainSec = sleep_cmd(5);
printf("remain second: %d\n", remainSec);
/*setitimer(ITIMER_REAL, &its, NULL);*/
while(1)
{
sleep(10);
raise(SIGKILL);
}
return 0;
}
|