distrib/utils/more/output.c

   1 /*      $NetBSD: output.c,v 1.7 2003/10/13 14:34:25 agc Exp $   */
   2
   3 /*
   4  * Copyright (c) 1988 Mark Nudelman
   5  * Copyright (c) 1988, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)output.c    8.2 (Berkeley) 4/27/95";
  37 #else
  38 __RCSID("$NetBSD: output.c,v 1.7 2003/10/13 14:34:25 agc Exp $");
  39 #endif
  40 #endif /* not lint */
  41
  42 /*
  43  * High level routines dealing with the output to the screen.
  44  */
  45
  46 #include <stdio.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49 #include <stdlib.h>
  50
  51 #include "less.h"
  52 #include "extern.h"
  53
  54 int errmsgs;    /* Count of messages displayed by error() */
  55
  56 /* display the line which is in the line buffer. */
  57 void
  58 put_line()
  59 {
  60         char *p;
  61         int c;
  62         int column;
  63
  64         if (sigs)
  65         {
  66                 /*
  67                  * Don't output if a signal is pending.
  68                  */
  69                 screen_trashed = 1;
  70                 return;
  71         }
  72
  73         if (line == NULL)
  74                 line = "";
  75
  76         column = 0;
  77         for (p = line;  *p != '\0';  p++)
  78         {
  79                 switch (c = *p)
  80                 {
  81                 case UL_CHAR:
  82                         ul_enter();
  83                         column += ul_width +1;
  84                         break;
  85                 case UE_CHAR:
  86                         ul_exit();
  87                         column += ue_width;
  88                         break;
  89                 case BO_CHAR:
  90                         bo_enter();
  91                         column += bo_width +1;
  92                         break;
  93                 case BE_CHAR:
  94                         bo_exit();
  95                         column += be_width;
  96                         break;
  97                 case '\t':
  98                         do
  99                         {
 100                                 putchr(' ');
 101                                 column++;
 102                         } while ((column % tabstop) != 0);
 103                         break;
 104                 case '\b':
 105                         putbs();
 106                         column--;
 107                         break;
 108                 default:
 109                         if (c & 0200)
 110                         {
 111                                 /*
 112                                  * Control characters arrive here as the
 113                                  * normal character [CARAT_CHAR(c)] with
 114                                  * the 0200 bit set.  See pappend().
 115                                  */
 116                                 putchr('^');
 117                                 putchr(c & 0177);
 118                                 column += 2;
 119                         } else
 120                         {
 121                                 putchr(c);
 122                                 column++;
 123                         }
 124                 }
 125         }
 126         if (column < sc_width || !auto_wrap || ignaw)
 127                 putchr('\n');
 128 }
 129
 130 static char obuf[1024];
 131 static char *ob = obuf;
 132
 133 /*
 134  * Flush buffered output.
 135  */
 136 void
 137 flush()
 138 {
 139         int n;
 140
 141         n = ob - obuf;
 142         if (n == 0)
 143                 return;
 144         if (write(1, obuf, n) != n)
 145                 screen_trashed = 1;
 146         ob = obuf;
 147 }
 148
 149 /*
 150  * Purge any pending output.
 151  */
 152 void
 153 purge()
 154 {
 155
 156         ob = obuf;
 157 }
 158
 159 /*
 160  * Output a character.
 161  */
 162 int
 163 putchr(c)
 164         int c;
 165 {
 166         if (ob >= &obuf[sizeof(obuf)])
 167                 flush();
 168         *ob++ = c;
 169         return c;
 170 }
 171
 172 /*
 173  * Output a string.
 174  */
 175 void
 176 putstr(s)
 177         char *s;
 178 {
 179         while (*s != '\0')
 180                 putchr(*s++);
 181 }
 182
 183 int cmdstack;
 184 static char return_to_continue[] = "(press RETURN)";
 185
 186 /*
 187  * Output a message in the lower left corner of the screen
 188  * and wait for carriage return.
 189  */
 190 void
 191 error(s)
 192         char *s;
 193 {
 194         int ch;
 195
 196         ++errmsgs;
 197         if (!any_display) {
 198                 /*
 199                  * Nothing has been displayed yet.  Output this message on
 200                  * error output (file descriptor 2) and don't wait for a
 201                  * keystroke to continue.
 202                  *
 203                  * This has the desirable effect of producing all error
 204                  * messages on error output if standard output is directed
 205                  * to a file.  It also does the same if we never produce
 206                  * any real output; for example, if the input file(s) cannot
 207                  * be opened.  If we do eventually produce output, code in
 208                  * edit() makes sure these messages can be seen before they
 209                  * are overwritten or scrolled away.
 210                  */
 211                 if (s != NULL) {
 212                         (void)write(2, s, strlen(s));
 213                         (void)write(2, "\n", 1);
 214                 }
 215                 return;
 216         }
 217
 218         lower_left();
 219         clear_eol();
 220         so_enter();
 221         if (s != NULL) {
 222                 putstr(s);
 223                 putstr("  ");
 224         }
 225         putstr(return_to_continue);
 226         so_exit();
 227
 228         if ((ch = getchr()) != '\n') {
 229                 if (ch == 'q')
 230                         quit();
 231                 cmdstack = ch;
 232         }
 233         lower_left();
 234
 235         if ((s != NULL ? strlen(s) : 0) + sizeof(return_to_continue) +
 236                 so_width + se_width + 1 > sc_width)
 237                 /*
 238                  * Printing the message has probably scrolled the screen.
 239                  * {{ Unless the terminal doesn't have auto margins,
 240                  *    in which case we just hammered on the right margin. }}
 241                  */
 242                 repaint();
 243         flush();
 244 }
 245
 246 static char intr_to_abort[] = "... (interrupt to abort)";
 247
 248 void
 249 ierror(s)
 250         char *s;
 251 {
 252         lower_left();
 253         clear_eol();
 254         so_enter();
 255         putstr(s);
 256         putstr(intr_to_abort);
 257         so_exit();
 258         flush();
 259 }