example23.c

LinuxNetProgramming Linux网络编程基础实例

#include 	<stdlib.h>
#include	<fcntl.h>
#include 	<errno.h>
#include 	<stdio.h>

#define		SERV_FIFO		"/tmp/fifo.serv"
#define		LINE			1024

int
main()
{
	int		readf, writef, dummyfd, fd;
	char		*ptr, buff[LINE], fifoname[LINE];
	pid_t	pid;
	ssize_t	n;

			/* create fifo use wellknow pathname */
	if ((mkfifo(SERV_FIFO,  666 < 0) && (errno != EEXIST)))
		printf("can't create fifo");

	readf = open(SERV_FIFO, O_RDONLY, 0);		/* open the fifo with read only mode */
	dummyfd = open(SERV_FIFO, O_WRONLY, 0);	/* open the fifo with write only mode */
	while ((n = getline(buff, 100, readf)) > 0) {
		if (buff[n-1] == '\n')
			n--;							/* delete the return character */
		buff[n] = '\0';					/* end the pathname with null character */
		if ((ptr = strchr(buff, ' ')) == NULL) {
			printf("bogus request: %s", buff);
			continue;
		}
		*ptr++ = 0;
		pid = atoi(buff);
					/* create the pathname of the client's fifo */
		snprintf(fifoname, sizeof(fifoname), "/tmp/fifo.%ld", (long)pid);
		if ((writef = open(fifoname, O_WRONLY, 0)) < 0) {
			printf("cannot open: %s", fifoname);
			continue;
		}
		if ((fd = open(ptr, O_WRONLY)) < 0) {
			snprintf(buff + n, sizeof(buff) - n, ": can't open, %s\n",strerror(errno));
			n = strlen(ptr);
			write(writef, ptr, n);			/* write the file to the client's fifo */
			close(writef);
		}
		else {
			while ((n = read(fd, buff, LINE)) > 0)
				write(writef, buff, n);
			close(fd);
			close(writef);
		}
	}
	exit(0);
}