contrib/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  * $FreeBSD: src/contrib/top/screen.c,v 1.2.6.1 2000/09/20 02:27:57 jkh Exp $
  12  * $DragonFly: src/contrib/top/screen.c,v 1.2 2003/06/17 04:24:07 dillon Exp $
  13  */
  14
  15 /*  This file contains the routines that interface to termcap and stty/gtty.
  16  *
  17  *  Paul Vixie, February 1987: converted to use ioctl() instead of stty/gtty.
  18  *
  19  *  I put in code to turn on the TOSTOP bit while top was running, but I
  20  *  didn't really like the results.  If you desire it, turn on the
  21  *  preprocessor variable "TOStop".   --wnl
  22  */
  23
  24 #include "os.h"
  25 #include "top.h"
  26
  27 #include <sys/ioctl.h>
  28 #include <curses.h>
  29 #include <term.h>
  30 #include <termios.h>
  31 #include "screen.h"
  32 #include "boolean.h"
  33
  34 extern char *myname;
  35
  36 int  overstrike;
  37 int  screen_length;
  38 int  screen_width;
  39 char ch_erase;
  40 char ch_kill;
  41 char smart_terminal;
  42 char PC;
  43 char termcap_buf[1024];
  44 char string_buffer[1024];
  45 char home[15];
  46 char lower_left[15];
  47 char *clear_line;
  48 char *clear_the_screen;
  49 char *clear_to_end;
  50 char *cursor_motion;
  51 char *start_standout;
  52 char *end_standout;
  53 char *terminal_init;
  54 char *terminal_end;
  55
  56 static struct termios old_settings;
  57 static struct termios new_settings;
  58 static char is_a_terminal = No;
  59
  60 #define STDIN   0
  61 #define STDOUT  1
  62 #define STDERR  2
  63
  64 void
  65 init_termcap(int interactive)
  66 {
  67     char *bufptr;
  68     char *PCptr;
  69     char *term_name;
  70     int status;
  71
  72     /* set defaults in case we aren't smart */
  73     screen_width = MAX_COLS;
  74     screen_length = 0;
  75
  76     if (!interactive)
  77     {
  78         /* pretend we have a dumb terminal */
  79         smart_terminal = No;
  80         return;
  81     }
  82
  83     /* assume we have a smart terminal until proven otherwise */
  84     smart_terminal = Yes;
  85
  86     /* get the terminal name */
  87     term_name = getenv("TERM");
  88
  89     /* if there is no TERM, assume it's a dumb terminal */
  90     /* patch courtesy of Sam Horrocks at telegraph.ics.uci.edu */
  91     if (term_name == NULL)
  92     {
  93         smart_terminal = No;
  94         return;
  95     }
  96
  97     /* now get the termcap entry */
  98     if ((status = tgetent(termcap_buf, term_name)) != 1)
  99     {
 100         if (status == -1)
 101         {
 102             fprintf(stderr, "%s: can't open termcap file\n", myname);
 103         }
 104         else
 105         {
 106             fprintf(stderr, "%s: no termcap entry for a `%s' terminal\n",
 107                     myname, term_name);
 108         }
 109
 110         /* pretend it's dumb and proceed */
 111         smart_terminal = No;
 112         return;
 113     }
 114
 115     /* "hardcopy" immediately indicates a very stupid terminal */
 116     if (tgetflag("hc"))
 117     {
 118         smart_terminal = No;
 119         return;
 120     }
 121
 122     /* set up common terminal capabilities */
 123     if ((screen_length = tgetnum("li")) <= 0)
 124     {
 125         screen_length = smart_terminal = 0;
 126         return;
 127     }
 128
 129     /* screen_width is a little different */
 130     if ((screen_width = tgetnum("co")) == -1)
 131     {
 132         screen_width = 79;
 133     }
 134     else
 135     {
 136         screen_width -= 1;
 137     }
 138
 139     /* terminals that overstrike need special attention */
 140     overstrike = tgetflag("os");
 141
 142     /* initialize the pointer into the termcap string buffer */
 143     bufptr = string_buffer;
 144
 145     /* get "ce", clear to end */
 146     if (!overstrike)
 147     {
 148         clear_line = tgetstr("ce", &bufptr);
 149     }
 150
 151     /* get necessary capabilities */
 152     if ((clear_the_screen  = tgetstr("cl", &bufptr)) == NULL ||
 153         (cursor_motion = tgetstr("cm", &bufptr)) == NULL)
 154     {
 155         smart_terminal = No;
 156         return;
 157     }
 158
 159     /* get some more sophisticated stuff -- these are optional */
 160     clear_to_end   = tgetstr("cd", &bufptr);
 161     terminal_init  = tgetstr("ti", &bufptr);
 162     terminal_end   = tgetstr("te", &bufptr);
 163     start_standout = tgetstr("so", &bufptr);
 164     end_standout   = tgetstr("se", &bufptr);
 165
 166     /* pad character */
 167     PC = (PCptr = tgetstr("pc", &bufptr)) ? *PCptr : 0;
 168
 169     /* set convenience strings */
 170     (void) strncpy(home, tgoto(cursor_motion, 0, 0), sizeof(home) - 1);
 171     home[sizeof(home) - 1] = '\0';
 172     /* (lower_left is set in get_screensize) */
 173
 174     /* get the actual screen size with an ioctl, if needed */
 175     /* This may change screen_width and screen_length, and it always
 176        sets lower_left. */
 177     get_screensize();
 178
 179     /* if stdout is not a terminal, pretend we are a dumb terminal */
 180     if (tcgetattr(STDOUT, &old_settings) == -1)
 181     {
 182         smart_terminal = No;
 183     }
 184 }
 185
 186 void
 187 init_screen(void)
 188 {
 189     if (tcgetattr(STDOUT, &old_settings) != -1)
 190     {
 191         /* copy the settings so we can modify them */
 192         new_settings = old_settings;
 193
 194         /* turn off ICANON, character echo and tab expansion */
 195         new_settings.c_lflag &= ~(ICANON|ECHO);
 196         new_settings.c_oflag &= ~(OXTABS);
 197         new_settings.c_cc[VMIN] = 1;
 198         new_settings.c_cc[VTIME] = 0;
 199         (void) tcsetattr(STDOUT, TCSADRAIN, &new_settings);
 200
 201         /* remember the erase and kill characters */
 202         ch_erase = old_settings.c_cc[VERASE];
 203         ch_kill  = old_settings.c_cc[VKILL];
 204
 205         /* remember that it really is a terminal */
 206         is_a_terminal = Yes;
 207
 208         /* send the termcap initialization string */
 209         putcap(terminal_init);
 210     }
 211
 212     if (!is_a_terminal)
 213     {
 214         /* not a terminal at all---consider it dumb */
 215         smart_terminal = No;
 216     }
 217 }
 218
 219 void
 220 end_screen(void)
 221 {
 222     /* move to the lower left, clear the line and send "te" */
 223     if (smart_terminal)
 224     {
 225         putcap(lower_left);
 226         putcap(clear_line);
 227         fflush(stdout);
 228         putcap(terminal_end);
 229     }
 230
 231     /* if we have settings to reset, then do so */
 232     if (is_a_terminal)
 233     {
 234         (void) tcsetattr(STDOUT, TCSADRAIN, &old_settings);
 235     }
 236 }
 237
 238 void
 239 reinit_screen(void)
 240 {
 241     /* install our settings if it is a terminal */
 242     if (is_a_terminal)
 243     {
 244         (void) tcsetattr(STDOUT, TCSADRAIN, &new_settings);
 245     }
 246
 247     /* send init string */
 248     if (smart_terminal)
 249     {
 250         putcap(terminal_init);
 251     }
 252 }
 253
 254 void
 255 get_screensize(void)
 256 {
 257
 258 #ifdef TIOCGWINSZ
 259
 260     struct winsize ws;
 261
 262     if (ioctl (1, TIOCGWINSZ, &ws) != -1)
 263     {
 264         if (ws.ws_row != 0)
 265         {
 266             screen_length = ws.ws_row;
 267         }
 268         if (ws.ws_col != 0)
 269         {
 270             screen_width = ws.ws_col - 1;
 271         }
 272     }
 273
 274 #else
 275 #ifdef TIOCGSIZE
 276
 277     struct ttysize ts;
 278
 279     if (ioctl (1, TIOCGSIZE, &ts) != -1)
 280     {
 281         if (ts.ts_lines != 0)
 282         {
 283             screen_length = ts.ts_lines;
 284         }
 285         if (ts.ts_cols != 0)
 286         {
 287             screen_width = ts.ts_cols - 1;
 288         }
 289     }
 290
 291 #endif /* TIOCGSIZE */
 292 #endif /* TIOCGWINSZ */
 293
 294     (void) strncpy(lower_left, tgoto(cursor_motion, 0, screen_length - 1),
 295         sizeof(lower_left) - 1);
 296     lower_left[sizeof(lower_left) - 1] = '\0';
 297 }
 298
 299 void
 300 dostandout(const char *msg)
 301 {
 302     if (smart_terminal)
 303     {
 304         putcap(start_standout);
 305         fputs(msg, stdout);
 306         putcap(end_standout);
 307     }
 308     else
 309     {
 310         fputs(msg, stdout);
 311     }
 312 }
 313
 314 void
 315 clear_myscreen(void)
 316 {
 317     if (smart_terminal)
 318     {
 319        putcap(clear_screen);
 320     }
 321 }
 322
 323 int
 324 clear_eol(int len)
 325 {
 326     if (smart_terminal && !overstrike && len > 0)
 327     {
 328         if (clear_line)
 329         {
 330             putcap(clear_line);
 331             return(0);
 332         }
 333         else
 334         {
 335             while (len-- > 0)
 336             {
 337                 putchar(' ');
 338             }
 339             return(1);
 340         }
 341     }
 342     return(-1);
 343 }
 344
 345 void
 346 go_home(void)
 347 {
 348     if (smart_terminal)
 349     {
 350         putcap(home);
 351     }
 352 }
 353
 354 /* This has to be defined as a subroutine for tputs (instead of a macro) */
 355
 356 int
 357 putstdout(int ch)
 358 {
 359     return(putchar(ch));
 360 }
 361