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io.c revision 1.1 
      1 /*
      2  * Copyright (c) 1983 Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 static char sccsid[] = "@(#)io.c	5.6 (Berkeley) 3/1/91";
     36 #endif /* not lint */
     37 
     38 /*
     39  * This file contains the I/O handling and the exchange of
     40  * edit characters. This connection itself is established in
     41  * ctl.c
     42  */
     43 
     44 #include <sys/time.h>
     45 #include "talk.h"
     46 #include <stdio.h>
     47 #include <errno.h>
     48 #include <string.h>
     49 
     50 #define A_LONG_TIME 10000000
     51 #define STDIN_MASK (1<<fileno(stdin))	/* the bit mask for standard
     52 					   input */
     53 
     54 /*
     55  * The routine to do the actual talking
     56  */
     57 talk()
     58 {
     59 	register int read_template, sockt_mask;
     60 	int read_set, nb;
     61 	char buf[BUFSIZ];
     62 	struct timeval wait;
     63 
     64 	message("Connection established\007\007\007");
     65 	current_line = 0;
     66 	sockt_mask = (1<<sockt);
     67 
     68 	/*
     69 	 * Wait on both the other process (sockt_mask) and
     70 	 * standard input ( STDIN_MASK )
     71 	 */
     72 	read_template = sockt_mask | STDIN_MASK;
     73 	for (;;) {
     74 		read_set = read_template;
     75 		wait.tv_sec = A_LONG_TIME;
     76 		wait.tv_usec = 0;
     77 		nb = select(32, &read_set, 0, 0, &wait);
     78 		if (nb <= 0) {
     79 			if (errno == EINTR) {
     80 				read_set = read_template;
     81 				continue;
     82 			}
     83 			/* panic, we don't know what happened */
     84 			p_error("Unexpected error from select");
     85 			quit();
     86 		}
     87 		if (read_set & sockt_mask) {
     88 			/* There is data on sockt */
     89 			nb = read(sockt, buf, sizeof buf);
     90 			if (nb <= 0) {
     91 				message("Connection closed. Exiting");
     92 				quit();
     93 			}
     94 			display(&his_win, buf, nb);
     95 		}
     96 		if (read_set & STDIN_MASK) {
     97 			/*
     98 			 * We can't make the tty non_blocking, because
     99 			 * curses's output routines would screw up
    100 			 */
    101 			ioctl(0, FIONREAD, (struct sgttyb *) &nb);
    102 			nb = read(0, buf, nb);
    103 			display(&my_win, buf, nb);
    104 			/* might lose data here because sockt is non-blocking */
    105 			write(sockt, buf, nb);
    106 		}
    107 	}
    108 }
    109 
    110 extern	int errno;
    111 extern	int sys_nerr;
    112 
    113 /*
    114  * p_error prints the system error message on the standard location
    115  * on the screen and then exits. (i.e. a curses version of perror)
    116  */
    117 p_error(string)
    118 	char *string;
    119 {
    120 	wmove(my_win.x_win, current_line%my_win.x_nlines, 0);
    121 	wprintw(my_win.x_win, "[%s : %s (%d)]\n",
    122 	    string, strerror(errno), errno);
    123 	wrefresh(my_win.x_win);
    124 	move(LINES-1, 0);
    125 	refresh();
    126 	quit();
    127 }
    128 
    129 /*
    130  * Display string in the standard location
    131  */
    132 message(string)
    133 	char *string;
    134 {
    135 
    136 	wmove(my_win.x_win, current_line%my_win.x_nlines, 0);
    137 	wprintw(my_win.x_win, "[%s]\n", string);
    138 	wrefresh(my_win.x_win);
    139 }
    140