myalarm

myalarm.c
  1 #include<stdio.h>
  2 #include<signal.h>
  3 #include<stdlib.h>
  4 #include<sys/time.h>
  5 #include<unistd.h>
  6 #include<errno.h>
  7 #include"myalarm.h"
  8 
  9 static int inited;
 10 typedef struct anyalarm
 11 {
 12     int sec;
 13     void (*fcntl)(void *);//函数指针(它是一个指针，它指向一个函数的地址)，用来接受字符串，并打印出来，
 14     char *str;//接受字符串的首地址
 15 }ANYALRM;
 16 static ANYALRM *alr[ALRSIZE];
 17 static struct sigaction oldact;
 18 static struct itimerval olditv;
 19 
 20 static void alrm_handler(int s)
 21 {
 22 //    printf("111\n");
 23     for(int i=0;i<ALRSIZE;i++)
 24     {
 25         if(alr[i] != NULL)
 26         {
 27             alr[i]->sec -= 1;
 28             if(alr[i]->sec==0)//当秒为0的时候则输出字符串
 29             {
 30                 alr[i]->fcntl(alr[i]->str);//通过函数指针打印出来字符串，
 31                 free(alr[i]);
 32                 alr[i]=NULL;//清空数组中的地址
 33             }
 34         }
 35 
 36     }
 37 }
 38 void moduler_load(void)
 39 {
 40     struct sigaction act;//改变信号行为
 41     struct itimerval itv;
 42 
 43     act.sa_handler = alrm_handler;
 44     act.sa_flags = 0;
 45     sigemptyset(&act.sa_mask);
 46     sigaction(SIGALRM,&act,&oldact);
 47 
 48     itv.it_interval.tv_sec = 1;
 49     itv.it_interval.tv_usec = 0;
 50     itv.it_value.tv_sec = 1;
 51     itv.it_value.tv_usec = 0;
 52     setitimer(ITIMER_REAL,&itv,&olditv);
 53 
 54     atexit(moduler_unload);//取消挂载，使闹钟恢复默认状态
 55     
 56 }
 57 void moduler_unload(void)//信号行为和时钟的恢复
 58 {
 59     sigaction(SIGALRM,&oldact,NULL);
 60     setitimer(ITIMER_REAL,&olditv,NULL);
 61 }
 62 
 63 void any1(void *s)
 64 {
 65     printf("%s",(char *)s);
 66     fflush(NULL);
 67 }
 68 void any2(void *s)
 69 {
 70     printf("%s",(char *)s);
 71     fflush(NULL);
 72 }
 73 void any3(void *s)
 74 {
 75     printf("%s",(char *)s);
 76     fflush(NULL);
 77 }
 78 
 79 
 80 int alr_init(int sec,void (*fcntl)(void *),char *str)
 81 {
 82     ANYALRM *alrm = NULL;
 83     if(inited ==0)
 84     {
 85         moduler_load();
 86         inited = 1;
 87     }
 88     alrm=malloc(sizeof(ANYALRM));
 89     if(alrm != NULL)
 90     {
 91     //    fprintf(stderr,"malloc is failed!\n");
 92         alrm->sec = sec;
 93         alrm->fcntl = fcntl;
 94         alrm->str = str;
 95         for(int i=0;i<ALRSIZE;i++)
 96         {
 97             if(alr[i]==NULL)
 98             {
 99                 alr[i]=alrm;
100                 return i;
101             }
102         }
103         return -1;
104     }
105 }
106 void anytimer_alarm(int sec,void(*fcntl)(void *),char *str)
107 {
108     if(alr_init(sec,fcntl,str)<0)
109     {
110         fprintf(stderr,"*alr_init failer\n");
111         return ;
112     }
113 }

 myalarm.h
 1 #ifndef __MYALARM_H
 2 #define __MYALARM_H
 3 
 4 #define ALRSIZE 1024
 5 
 6 void any1(void *s);
 7 void any2(void *s);
 8 void any3(void *s);
 9 
10 void anytimer_alarm(int sec,void(*fcntl)(void *),char *str);
11 
12 int alr_init(int sec,void (*fcntl)(void *),char *str);
13 
14 void alarm_handler(int s);
15 
16 int alr_init(int sec,void(*fcntl)(void *),char *str);
17 
18 void moduler_load(void);
19 
20 void moduler_unload(void);
21 
22 
23 #endif


 makefile 
1 main : main.o myalarm.o 2 gcc main.o myalarm.o -o main 3 clean : 4 rm -rf *.o main