usr/src/lib/libcurses/screen/cbreak.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39
  40 #pragma ident   "%Z%%M% %I%     %E% SMI"
  41
  42 /*LINTLIBRARY*/
  43
  44 /*
  45  * Routines to deal with setting and resetting modes in the tty driver.
  46  * See also setupterm.c in the termlib part.
  47  */
  48 #include <sys/types.h>
  49 #include "curses_inc.h"
  50
  51 int
  52 cbreak(void)
  53 {
  54         /*
  55          * This optimization is here because till SVR3.1 curses did not come up
  56          * in cbreak mode and now it does.  Therefore, most programs when they
  57          * call cbreak won't pay for it since we'll know we're in the right
  58          * mode.
  59          */
  60
  61         if (cur_term->_fl_rawmode != 1) {
  62 #ifdef SYSV
  63         /*
  64          * You might ask why ICRNL has anything to do with cbreak.
  65          * The problem is that there are function keys that send
  66          * a carriage return (some hp's).  Curses cannot virtualize
  67          * these function keys if CR is being mapped to a NL.  Sooo,
  68          * when we start a program up we unmap those but if you are
  69          * in nocbreak then we map them back.  The reason for that is that
  70          * if a getch or getstr is done and you are in nocbreak the tty
  71          * driver won't return until it sees a new line and since we've
  72          * turned it off any program that has nl() and nocbreak() would
  73          * force the user to type a NL.  The problem with the function keys
  74          * only gets solved if you are in cbreak mode which is OK
  75          * since program taking action on a function key is probably
  76          * in cbreak because who would expect someone to press a function
  77          * key and then return ?????
  78          */
  79
  80                 PROGTTYS.c_iflag &= ~ICRNL;
  81                 PROGTTYS.c_lflag &= ~ICANON;
  82                 PROGTTYS.c_cc[VMIN] = 1;
  83                 PROGTTYS.c_cc[VTIME] = 0;
  84 #else
  85                 PROGTTY.sg_flags |= (CBREAK | CRMOD);
  86 #endif
  87
  88 #ifdef DEBUG
  89 #ifdef SYSV
  90                 if (outf)
  91                         fprintf(outf, "cbreak(), file %x, flags %x\n",
  92                             cur_term->Filedes, PROGTTYS.c_lflag);
  93 #else
  94                 if (outf)
  95                         fprintf(outf, "cbreak(), file %x, flags %x\n",
  96                             cur_term->Filedes, PROGTTY.sg_flags);
  97 #endif
  98 #endif
  99                 cur_term->_fl_rawmode = 1;
 100                 cur_term->_delay = -1;
 101                 (void) reset_prog_mode();
 102 #ifdef FIONREAD
 103                 cur_term->timeout = 0;
 104 #endif /* FIONREAD */
 105         }
 106         return (OK);
 107 }