一、信号处理函数的注册 signal()使用：

  1 #include<stdio.h>2 #include <signal.h>3 4 void handler(int signum)5 {6         switch(signum){7                 case 2:8                         printf("signum = %d\n",signum);9                         break;10                 case 9:11                         printf("signum = %d\n",signum);12                         break;13                 case 10:14                         printf("signum = %d\n",signum);15                         break;16         }17 }18 19 int main()20 {21         signal(SIGINT,handler);22         signal(SIGKILL,handler);23         signal(SIGUSR1,handler);24 25         while(1);26 27         return 0;28 }

二、信号处理发送函数kill()

刚才都是通过kill指令发信号，现在写个程序完成信号的发送

  1 #include<stdio.h>2 #include<stdlib.h>3 #include <signal.h>4 //int kill(pid_t pid, int sig);5 6 int main(int argc ,char *argv[])7 {8         int signum;9         int pid;10 11         signum=atoi(argv[1]);12         pid   =atoi(argv[2]);13         printf("signum=%d,pid=%d\n",signum,pid);14 15         kill(pid,signum);16         printf("kill ok\n");17         return 0;18 }

三、或者用system()调用脚本来杀

 

  1 #include<stdio.h>2 #include <stdlib.h>3 //int system(const char *command);4 5 int main(int argc,char *argv[])6 {7         int sig;8         int pid;9         sig = atoi(argv[1]);10         pid = atoi(argv[2]);11         printf("sig=%d,pid=%d\n",sig,pid);12 13         char cmd[32]={0};14         sprintf(cmd,"kill -%d %d",sig,pid);15         system(cmd);16         return 0;17 }
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四、信号携带消息----高级信号编程

 vi demo16.c

  1 #include<stdio.h>2 #include<signal.h>3 #include <unistd.h>4 //int sigaction(int signum, const struct sigaction *restrict act,5 //                             struct sigaction *restrict oldact);6 7 void handler(int sig, siginfo_t *info, void *ucontext)8 {9               printf("sig=%d\n",sig);10               if(ucontext!=NULL){11                         printf("data =%d\n",info->si_int);12                         printf("send pid =%d\n",info->si_pid);13               }14 15 }16 17 18 int main()19 {20         struct sigaction act;21         act.sa_flags = SA_SIGINFO;22         act.sa_sigaction = handler;23 24         printf("read pid=%d\n",getpid());25         sigaction(SIGUSR2,&act,NULL);26         while(1);27         return 0;28 }

vi demo17.c

  1 #include <unistd.h>2 #include<stdio.h>3 #include<stdlib.h>4 #include <signal.h>5 6 //int system(const char *command);7 //int sigqueue(pid_t pid, int sig, const union sigval value);8 int main(int argc,char *argv[])9 {10         int sig;11         int pid;12         sig = atoi(argv[1]);13         pid = atoi(argv[2]);14         printf("sig=%d,pid=%d\n",sig,pid);15 16         union sigval value;17         value.sival_int = 77;18         printf("my pid is %d\n",getpid());19         sigqueue(pid,sig,value);20         printf("send ok\n");21         return 0;22 }
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