usr.bin/top/screen.c

   1 /*
   2  *  Top users/processes display for Unix
   3  *  Version 3
   4  *
   5  *  This program may be freely redistributed,
   6  *  but this entire comment MUST remain intact.
   7  *
   8  *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
   9  *  Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
  10  */
  11
  12 /*  This file contains the routines that interface to termcap and stty/gtty.
  13  *
  14  *  Paul Vixie, February 1987: converted to use ioctl() instead of stty/gtty.
  15  *
  16  *  I put in code to turn on the TOSTOP bit while top was running, but I
  17  *  didn't really like the results.  If you desire it, turn on the
  18  *  preprocessor variable "TOStop".   --wnl
  19  */
  20
  21 #include <sys/ioctl.h>
  22
  23 #include <err.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <termios.h>
  27 #include <curses.h>
  28 #include <termcap.h>
  29 #include <unistd.h>
  30
  31 #include "screen.h"
  32 #include "top.h"
  33
  34 int  overstrike;
  35 int  screen_length;
  36 int  screen_width;
  37 char ch_erase;
  38 char ch_kill;
  39 char smart_terminal;
  40 static char termcap_buf[1024];
  41 static char string_buffer[1024];
  42 static char home[15];
  43 static char lower_left[15];
  44 char *clear_line;
  45 static char *clear_screen;
  46 char *clear_to_end;
  47 char *cursor_motion;
  48 static char *start_standout;
  49 static char *end_standout;
  50 static char *terminal_init;
  51 static char *terminal_end;
  52
  53 static struct termios old_settings;
  54 static struct termios new_settings;
  55 static char is_a_terminal = false;
  56
  57 #define NON_INTERACTIVE_MODE_VIRTUAL_SCREEN_WIDTH 1024
  58
  59 void
  60 init_termcap(bool interactive)
  61 {
  62     char *bufptr;
  63     char *PCptr;
  64     char *term_name;
  65     int status;
  66
  67     screen_width = 0;
  68     screen_length = 0;
  69
  70     if (!interactive)
  71     {
  72         /* pretend we have a dumb terminal */
  73         screen_width = NON_INTERACTIVE_MODE_VIRTUAL_SCREEN_WIDTH;
  74         smart_terminal = false;
  75         return;
  76     }
  77
  78     /* assume we have a smart terminal until proven otherwise */
  79     smart_terminal = true;
  80
  81     /* get the terminal name */
  82     term_name = getenv("TERM");
  83
  84     /* if there is no TERM, assume it's a dumb terminal */
  85     /* patch courtesy of Sam Horrocks at telegraph.ics.uci.edu */
  86     if (term_name == NULL)
  87     {
  88         smart_terminal = false;
  89         return;
  90     }
  91
  92     /* now get the termcap entry */
  93     if ((status = tgetent(termcap_buf, term_name)) != 1)
  94     {
  95         if (status == -1)
  96         {
  97             warnx("can't open termcap file");
  98         }
  99         else
 100         {
 101             warnx("no termcap entry for a `%s' terminal", term_name);
 102         }
 103
 104         /* pretend it's dumb and proceed */
 105         smart_terminal = false;
 106         return;
 107     }
 108
 109     /* "hardcopy" immediately indicates a very stupid terminal */
 110     if (tgetflag("hc"))
 111     {
 112         smart_terminal = false;
 113         return;
 114     }
 115
 116     /* set up common terminal capabilities */
 117     if ((screen_length = tgetnum("li")) <= 0)
 118     {
 119         screen_length = smart_terminal = 0;
 120         return;
 121     }
 122
 123     /* screen_width is a little different */
 124     if ((screen_width = tgetnum("co")) == -1)
 125     {
 126         screen_width = 79;
 127     }
 128     else
 129     {
 130         screen_width -= 1;
 131     }
 132
 133     /* terminals that overstrike need special attention */
 134     overstrike = tgetflag("os");
 135
 136     /* initialize the pointer into the termcap string buffer */
 137     bufptr = string_buffer;
 138
 139     /* get "ce", clear to end */
 140     if (!overstrike)
 141     {
 142                 clear_line = tgetstr("ce", &bufptr);
 143     }
 144
 145     /* get necessary capabilities */
 146     if ((clear_screen  = tgetstr("cl", &bufptr)) == NULL ||
 147         (cursor_motion = tgetstr("cm", &bufptr)) == NULL)
 148     {
 149         smart_terminal = false;
 150         return;
 151     }
 152
 153     /* get some more sophisticated stuff -- these are optional */
 154     clear_to_end   = tgetstr("cd", &bufptr);
 155     terminal_init  = tgetstr("ti", &bufptr);
 156     terminal_end   = tgetstr("te", &bufptr);
 157     start_standout = tgetstr("so", &bufptr);
 158     end_standout   = tgetstr("se", &bufptr);
 159
 160     /* pad character */
 161     PC = (PCptr = tgetstr("pc", &bufptr)) ? *PCptr : 0;
 162
 163     /* set convenience strings */
 164     strncpy(home, tgoto(cursor_motion, 0, 0), sizeof(home) - 1);
 165     home[sizeof(home) - 1] = '\0';
 166     /* (lower_left is set in get_screensize) */
 167
 168     /* get the actual screen size with an ioctl, if needed */
 169     /* This may change screen_width and screen_length, and it always
 170        sets lower_left. */
 171     get_screensize();
 172
 173     /* if stdout is not a terminal, pretend we are a dumb terminal */
 174     if (tcgetattr(STDOUT_FILENO, &old_settings) == -1)
 175     {
 176         smart_terminal = false;
 177     }
 178 }
 179
 180 void
 181 init_screen(void)
 182 {
 183     /* get the old settings for safe keeping */
 184     if (tcgetattr(STDOUT_FILENO, &old_settings) != -1)
 185     {
 186         /* copy the settings so we can modify them */
 187         new_settings = old_settings;
 188
 189         /* turn off ICANON, character echo and tab expansion */
 190         new_settings.c_lflag &= ~(ICANON|ECHO);
 191         new_settings.c_oflag &= ~(TAB3);
 192         new_settings.c_cc[VMIN] = 1;
 193         new_settings.c_cc[VTIME] = 0;
 194         tcsetattr(STDOUT_FILENO, TCSADRAIN, &new_settings);
 195
 196         /* remember the erase and kill characters */
 197         ch_erase = old_settings.c_cc[VERASE];
 198         ch_kill  = old_settings.c_cc[VKILL];
 199
 200         /* remember that it really is a terminal */
 201         is_a_terminal = true;
 202
 203         /* send the termcap initialization string */
 204         putcap(terminal_init);
 205     }
 206
 207     if (!is_a_terminal)
 208     {
 209         /* not a terminal at all---consider it dumb */
 210         smart_terminal = false;
 211     }
 212 }
 213
 214 void
 215 end_screen(void)
 216 {
 217     /* move to the lower left, clear the line and send "te" */
 218     if (smart_terminal)
 219     {
 220         putcap(lower_left);
 221         putcap(clear_line);
 222         fflush(stdout);
 223         putcap(terminal_end);
 224     }
 225
 226     /* if we have settings to reset, then do so */
 227     if (is_a_terminal)
 228     {
 229         tcsetattr(STDOUT_FILENO, TCSADRAIN, &old_settings);
 230     }
 231 }
 232
 233 void
 234 reinit_screen(void)
 235 {
 236     /* install our settings if it is a terminal */
 237     if (is_a_terminal)
 238     {
 239         tcsetattr(STDOUT_FILENO, TCSADRAIN, &new_settings);
 240     }
 241
 242     /* send init string */
 243     if (smart_terminal)
 244     {
 245         putcap(terminal_init);
 246     }
 247 }
 248
 249 void
 250 get_screensize(void)
 251 {
 252     struct winsize ws;
 253
 254     if (ioctl (1, TIOCGWINSZ, &ws) != -1)
 255     {
 256         if (ws.ws_row != 0)
 257         {
 258             screen_length = ws.ws_row;
 259         }
 260         if (ws.ws_col != 0)
 261         {
 262             screen_width = ws.ws_col - 1;
 263         }
 264     }
 265
 266
 267     (void) strncpy(lower_left, tgoto(cursor_motion, 0, screen_length - 1),
 268         sizeof(lower_left) - 1);
 269     lower_left[sizeof(lower_left) - 1] = '\0';
 270 }
 271
 272 void
 273 top_standout(const char *msg)
 274 {
 275     if (smart_terminal)
 276     {
 277         putcap(start_standout);
 278         fputs(msg, stdout);
 279         putcap(end_standout);
 280     }
 281     else
 282     {
 283         fputs(msg, stdout);
 284     }
 285 }
 286
 287 void
 288 top_clear(void)
 289 {
 290     if (smart_terminal)
 291     {
 292         putcap(clear_screen);
 293     }
 294 }
 295
 296 int
 297 clear_eol(int len)
 298 {
 299     if (smart_terminal && !overstrike && len > 0)
 300     {
 301         if (clear_line)
 302         {
 303             putcap(clear_line);
 304             return(0);
 305         }
 306         else
 307         {
 308             while (len-- > 0)
 309             {
 310                 putchar(' ');
 311             }
 312             return(1);
 313         }
 314     }
 315     return(-1);
 316 }