prg4_8server.c

配套光盘网络编程进程间的通信,网络编程进程间的通信是一本很经典的好书

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include "fifo.h"
#include <readline/readline.h>
#include <readline/history.h>
#include <fcntl.h>

#define	MAXLINE	100
#define 	FILE_MODE	(S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)

int main(int argc,char **argv)
{
	int readfifo,writefifo,dummyfd,fd;
	char *ptr,buff[MAXLINE],fifoname[MAXLINE];
	char 	serr[256] = {0};
	pid_t	pid;
	size_t	n;
	
	if ((mkfifo(SERV_FIFO,FILE_MODE) <0) && (errno != EEXIST))
	{
		sprintf(serr,"can't create %s",SERV_FIFO);
		perror(serr);
		exit(0);			
	}
	readfifo = open(SERV_FIFO,O_RDONLY,0);
	dummyfd = open(SERV_FIFO,O_WRONLY,0);	//never used
	while( (n =read(readfifo,buff,MAXLINE))>0)
	{
		if (buff[n-1] == '\n')
		  n--;
		buff[n] = '\0';
		if ((ptr = strchr(buff,' ')) ==  NULL)
		{
			sprintf(serr,"bogus  request:%s",buff);
			perror(serr);
			continue;
		}
		*ptr++ = 0;	//ptr = pathname
		pid = atol(buff);
		snprintf(fifoname,sizeof(fifoname),"/tmp/fifo.%ld",(long)pid);
		if ((writefifo = open(fifoname,O_WRONLY,0)) <0)
		{
			sprintf(serr,"can't open:%s",fifoname);
			perror(serr);
			continue;
		}
		
		if ((fd = open(ptr,O_RDONLY)) <0)
		{
			snprintf(buff+n,sizeof(buff)-n,":can't open:%s\n",
			strerror(errno));
			n = strlen(ptr);
			write(writefifo,ptr,n);
			close(writefifo);
		}
		else
		{
			while( (n = read(fd,buff,MAXLINE)) > 0)
				write(writefifo,buff,n);
			close(fd);
			close(writefifo);
		}
	}
	exit(0);
}