syslog_dameon.c

关于进程间通信的代码集锦

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<fcntl.h>
#include<sys/types.h>
#include<unistd.h>
#include<sys/wait.h>
#include<syslog.h>

#define MAXFILE 65535
int main()
{
	pid_t pc;
	int i,fd,len;
	char* buf;
	len=strlen(buf);
	pc=fork();
	if(pc<0)
	{
		printf("error fork\n");
		exit(1);
	}
	else if(pc>0)
	{
		exit(0);
	}
	openlog("demo_dameon",LOG_PID,LOG_DAEMON);
	pid_t sid;
	if((sid=setsid())<0)
	{
		syslog(LOG_ERR,"%s\n","setsid");
		exit(1);
	}
	if((sid=chdir("/"))<0)
	{
		syslog(LOG_ERR,"%s\n","setsid");
		exit(1);
	}
	umask(0);
	for(i=0;i<MAXFILE;i++)
	{
		close(i);
	}

	fd=open("/tmp/dameon.log",O_CREAT|O_WRONLY|O_APPEND,0600);
	if(fd<0)
	{
		syslog(LOG_ERR,"open");
		exit(1);
	}
	while(1)
	{
		write(fd,buf,len+1);
		sleep(10);
	}
	close(fd);
}