#include	"open.h"#include	<sys/uio.h>		/* struct iovec *//* * Open the file by sending the "name" and "oflag" to the * connection server and reading a file descriptor back. */intcsopen(char *name, int oflag){	pid_t			pid;	int				len;	char			buf[10];	struct iovec	iov[3];	static int		fd[2] = { -1, -1 };	if (fd[0] < 0) {	/* fork/exec our open server first time */		if (s_pipe(fd) < 0)			err_sys("s_pipe error");		if ((pid = fork()) < 0) {			err_sys("fork error");		} else if (pid == 0) {		/* child */			close(fd[0]);			if (fd[1] != STDIN_FILENO &&			  dup2(fd[1], STDIN_FILENO) != STDIN_FILENO)				err_sys("dup2 error to stdin");			if (fd[1] != STDOUT_FILENO &&			  dup2(fd[1], STDOUT_FILENO) != STDOUT_FILENO)				err_sys("dup2 error to stdout");			if (execl("./opend", "opend", (char *)0) < 0)				err_sys("execl error");		}		close(fd[1]);				/* parent */	}	sprintf(buf, " %d", oflag);		/* oflag to ascii */	iov[0].iov_base = CL_OPEN " ";		/* string concatenation */	iov[0].iov_len  = strlen(CL_OPEN) + 1;	iov[1].iov_base = name;	iov[1].iov_len  = strlen(name);	iov[2].iov_base = buf;	iov[2].iov_len  = strlen(buf) + 1;	/* +1 for null at end of buf */	len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;	if (writev(fd[0], &iov[0], 3) != len)		err_sys("writev error");	/* read descriptor, returned errors handled by write() */	return(recv_fd(fd[0], write));}