4.4BSD/usr/src/contrib/mh-6.8/miscellany/less-177/screen.c
/*
* Routines which deal with the characteristics of the terminal.
* Uses termcap to be as terminal-independent as possible.
*
* {{ Someday this should be rewritten to use curses. }}
*/
#include "less.h"
#if XENIX
#include <sys/types.h>
#include <sys/ioctl.h>
#endif
#if TERMIO
#include <termio.h>
#else
#include <sgtty.h>
#endif
#if !TERMIO && defined(TIOCGWINSZ)
#include <sys/ioctl.h>
#else
/*
* For the Unix PC (ATT 7300 & 3B1):
* Since WIOCGETD is defined in sys/window.h, we can't use that to decide
* whether to include sys/window.h. Use SIGPHONE from signal.h instead.
*/
#include <signal.h>
#ifdef SIGPHONE
#include <sys/window.h>
#endif
#endif
#if NEED_PTEM_H && defined(TIOCGWINSZ)
/*
* All this just to get struct winsize. Sigh.
*/
#include <sys/types.h>
#include <sys/stream.h>
#include <sys/ptem.h>
#endif
/*
* Strings passed to tputs() to do various terminal functions.
*/
static char
*sc_pad, /* Pad string */
*sc_home, /* Cursor home */
*sc_addline, /* Add line, scroll down following lines */
*sc_lower_left, /* Cursor to last line, first column */
*sc_move, /* General cursor positioning */
*sc_clear, /* Clear screen */
*sc_eol_clear, /* Clear to end of line */
*sc_s_in, /* Enter standout (highlighted) mode */
*sc_s_out, /* Exit standout mode */
*sc_u_in, /* Enter underline mode */
*sc_u_out, /* Exit underline mode */
*sc_b_in, /* Enter bold mode */
*sc_b_out, /* Exit bold mode */
*sc_bl_in, /* Enter blink mode */
*sc_bl_out, /* Exit blink mode */
*sc_visual_bell, /* Visual bell (flash screen) sequence */
*sc_backspace, /* Backspace cursor */
*sc_init, /* Startup terminal initialization */
*sc_deinit; /* Exit terminal de-initialization */
static int init_done = 0;
public int auto_wrap; /* Terminal does \r\n when write past margin */
public int ignaw; /* Terminal ignores \n immediately after wrap */
public int erase_char, kill_char; /* The user's erase and line-kill chars */
public int sc_width, sc_height; /* Height & width of screen */
public int bo_s_width, bo_e_width; /* Printing width of boldface seq */
public int ul_s_width, ul_e_width; /* Printing width of underline seq */
public int so_s_width, so_e_width; /* Printing width of standout seq */
public int bl_s_width, bl_e_width; /* Printing width of blink seq */
static char *cheaper();
/*
* These two variables are sometimes defined in,
* and needed by, the termcap library.
* It may be necessary on some systems to declare them extern here.
*/
/*extern*/ short ospeed; /* Terminal output baud rate */
/*extern*/ char PC; /* Pad character */
extern int quiet; /* If VERY_QUIET, use visual bell for bell */
extern int know_dumb; /* Don't complain about a dumb terminal */
extern int back_scroll;
extern int swindow;
extern char *tgetstr();
extern char *tgoto();
extern char *getenv();
/*
* Change terminal to "raw mode", or restore to "normal" mode.
* "Raw mode" means
* 1. An outstanding read will complete on receipt of a single keystroke.
* 2. Input is not echoed.
* 3. On output, \n is mapped to \r\n.
* 4. \t is NOT expanded into spaces.
* 5. Signal-causing characters such as ctrl-C (interrupt),
* etc. are NOT disabled.
* It doesn't matter whether an input \n is mapped to \r, or vice versa.
*/
public void
raw_mode(on)
int on;
{
static int curr_on = 0;
if (on == curr_on)
return;
#if TERMIO
{
struct termio s;
static struct termio save_term;
if (on)
{
/*
* Get terminal modes.
*/
ioctl(2, TCGETA, &s);
/*
* Save modes and set certain variables dependent on modes.
*/
save_term = s;
ospeed = s.c_cflag & CBAUD;
erase_char = s.c_cc[VERASE];
kill_char = s.c_cc[VKILL];
/*
* Set the modes to the way we want them.
*/
s.c_lflag &= ~(ICANON|ECHO|ECHOE|ECHOK|ECHONL);
s.c_oflag |= (OPOST|ONLCR|TAB3);
s.c_oflag &= ~(OCRNL|ONOCR|ONLRET);
s.c_cc[VMIN] = 1;
s.c_cc[VTIME] = 0;
} else
{
/*
* Restore saved modes.
*/
s = save_term;
}
ioctl(2, TCSETAW, &s);
}
#else
{
struct sgttyb s;
static struct sgttyb save_term;
if (on)
{
/*
* Get terminal modes.
*/
ioctl(2, TIOCGETP, &s);
/*
* Save modes and set certain variables dependent on modes.
*/
save_term = s;
ospeed = s.sg_ospeed;
erase_char = s.sg_erase;
kill_char = s.sg_kill;
/*
* Set the modes to the way we want them.
*/
s.sg_flags |= CBREAK;
s.sg_flags &= ~(ECHO|XTABS);
} else
{
/*
* Restore saved modes.
*/
s = save_term;
}
ioctl(2, TIOCSETN, &s);
}
#endif
curr_on = on;
}
static void
cannot(s)
char *s;
{
PARG parg;
if (know_dumb)
/*
* User knows this is a dumb terminal, so don't tell him.
*/
return;
parg.p_string = s;
error("WARNING: terminal cannot %s", &parg);
}
/*
* Get size of the output screen.
*/
public void
scrsize(p_height, p_width)
int *p_height;
int *p_width;
{
register char *s;
#ifdef TIOCGWINSZ
struct winsize w;
#else
#ifdef WIOCGETD
struct uwdata w;
#endif
#endif
#ifdef TIOCGWINSZ
if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_row > 0)
*p_height = w.ws_row;
else
#else
#ifdef WIOCGETD
if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_height > 0)
*p_height = w.uw_height/w.uw_vs;
else
#endif
#endif
if ((s = getenv("LINES")) != NULL)
*p_height = atoi(s);
else
*p_height = tgetnum("li");
if (*p_height <= 0)
*p_height = 24;
#ifdef TIOCGWINSZ
if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_col > 0)
*p_width = w.ws_col;
else
#ifdef WIOCGETD
if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_width > 0)
*p_width = w.uw_width/w.uw_hs;
else
#endif
#endif
if ((s = getenv("COLUMNS")) != NULL)
*p_width = atoi(s);
else
*p_width = tgetnum("co");
if (*p_width <= 0)
*p_width = 80;
}
/*
* Get terminal capabilities via termcap.
*/
public void
get_term()
{
char *sp;
register char *t1, *t2;
register int hard;
char *term;
char termbuf[2048];
static char sbuf[1024];
/*
* Find out what kind of terminal this is.
*/
if ((term = getenv("TERM")) == NULL)
term = "unknown";
if (tgetent(termbuf, term) <= 0)
strcpy(termbuf, "dumb:hc:");
hard = tgetflag("hc");
/*
* Get size of the screen.
*/
scrsize(&sc_height, &sc_width);
pos_init();
if (swindow < 0)
swindow = sc_height - 1;
auto_wrap = tgetflag("am");
ignaw = tgetflag("xn");
/*
* Assumes termcap variable "sg" is the printing width of:
* the standout sequence, the end standout sequence,
* the underline sequence, the end underline sequence,
* the boldface sequence, and the end boldface sequence.
*/
if ((so_s_width = tgetnum("sg")) < 0)
so_s_width = 0;
so_e_width = so_s_width;
bo_s_width = bo_e_width = so_s_width;
ul_s_width = ul_e_width = so_s_width;
bl_s_width = bl_e_width = so_s_width;
/*
* Get various string-valued capabilities.
*/
sp = sbuf;
sc_pad = tgetstr("pc", &sp);
if (sc_pad != NULL)
PC = *sc_pad;
sc_init = tgetstr("ti", &sp);
if (sc_init == NULL)
sc_init = "";
sc_deinit= tgetstr("te", &sp);
if (sc_deinit == NULL)
sc_deinit = "";
sc_eol_clear = tgetstr("ce", &sp);
if (hard || sc_eol_clear == NULL || *sc_eol_clear == '\0')
{
cannot("clear to end of line");
sc_eol_clear = "";
}
sc_clear = tgetstr("cl", &sp);
if (hard || sc_clear == NULL || *sc_clear == '\0')
{
cannot("clear screen");
sc_clear = "\n\n";
}
sc_move = tgetstr("cm", &sp);
if (hard || sc_move == NULL || *sc_move == '\0')
{
/*
* This is not an error here, because we don't
* always need sc_move.
* We need it only if we don't have home or lower-left.
*/
sc_move = "";
}
sc_s_in = tgetstr("so", &sp);
if (hard || sc_s_in == NULL)
sc_s_in = "";
sc_s_out = tgetstr("se", &sp);
if (hard || sc_s_out == NULL)
sc_s_out = "";
sc_u_in = tgetstr("us", &sp);
if (hard || sc_u_in == NULL)
sc_u_in = sc_s_in;
sc_u_out = tgetstr("ue", &sp);
if (hard || sc_u_out == NULL)
sc_u_out = sc_s_out;
sc_b_in = tgetstr("md", &sp);
if (hard || sc_b_in == NULL)
{
sc_b_in = sc_s_in;
sc_b_out = sc_s_out;
} else
{
sc_b_out = tgetstr("me", &sp);
if (hard || sc_b_out == NULL)
sc_b_out = "";
}
sc_bl_in = tgetstr("mb", &sp);
if (hard || sc_bl_in == NULL)
{
sc_bl_in = sc_s_in;
sc_bl_out = sc_s_out;
} else
{
sc_bl_out = sc_b_out;
}
sc_visual_bell = tgetstr("vb", &sp);
if (hard || sc_visual_bell == NULL)
sc_visual_bell = "";
if (tgetflag("bs"))
sc_backspace = "\b";
else
{
sc_backspace = tgetstr("bc", &sp);
if (sc_backspace == NULL || *sc_backspace == '\0')
sc_backspace = "\b";
}
/*
* Choose between using "ho" and "cm" ("home" and "cursor move")
* to move the cursor to the upper left corner of the screen.
*/
t1 = tgetstr("ho", &sp);
if (hard || t1 == NULL)
t1 = "";
if (*sc_move == '\0')
t2 = "";
else
{
strcpy(sp, tgoto(sc_move, 0, 0));
t2 = sp;
sp += strlen(sp) + 1;
}
sc_home = cheaper(t1, t2, "home cursor", "|\b^");
/*
* Choose between using "ll" and "cm" ("lower left" and "cursor move")
* to move the cursor to the lower left corner of the screen.
*/
t1 = tgetstr("ll", &sp);
if (hard || t1 == NULL)
t1 = "";
if (*sc_move == '\0')
t2 = "";
else
{
strcpy(sp, tgoto(sc_move, 0, sc_height-1));
t2 = sp;
sp += strlen(sp) + 1;
}
sc_lower_left = cheaper(t1, t2,
"move cursor to lower left of screen", "\r");
/*
* Choose between using "al" or "sr" ("add line" or "scroll reverse")
* to add a line at the top of the screen.
*/
t1 = tgetstr("al", &sp);
if (hard || t1 == NULL)
t1 = "";
t2 = tgetstr("sr", &sp);
if (hard || t2 == NULL)
t2 = "";
sc_addline = cheaper(t1, t2, "scroll backwards", "");
if (*sc_addline == '\0')
{
/*
* Force repaint on any backward movement.
*/
back_scroll = 0;
}
}
/*
* Return the cost of displaying a termcap string.
* We use the trick of calling tputs, but as a char printing function
* we give it inc_costcount, which just increments "costcount".
* This tells us how many chars would be printed by using this string.
* {{ Couldn't we just use strlen? }}
*/
static int costcount;
/*ARGSUSED*/
static void
inc_costcount(c)
int c;
{
costcount++;
}
static int
cost(t)
char *t;
{
costcount = 0;
tputs(t, sc_height, inc_costcount);
return (costcount);
}
/*
* Return the "best" of the two given termcap strings.
* The best, if both exist, is the one with the lower
* cost (see cost() function).
*/
static char *
cheaper(t1, t2, doit, def)
char *t1, *t2;
char *doit;
char *def;
{
if (*t1 == '\0' && *t2 == '\0')
{
cannot(doit);
return (def);
}
if (*t1 == '\0')
return (t2);
if (*t2 == '\0')
return (t1);
if (cost(t1) < cost(t2))
return (t1);
return (t2);
}
/*
* Below are the functions which perform all the
* terminal-specific screen manipulation.
*/
/*
* Initialize terminal
*/
public void
init()
{
tputs(sc_init, sc_height, putchr);
init_done = 1;
}
/*
* Deinitialize terminal
*/
public void
deinit()
{
if (!init_done)
return;
tputs(sc_deinit, sc_height, putchr);
init_done = 0;
}
/*
* Home cursor (move to upper left corner of screen).
*/
public void
home()
{
tputs(sc_home, 1, putchr);
}
/*
* Add a blank line (called with cursor at home).
* Should scroll the display down.
*/
public void
add_line()
{
tputs(sc_addline, sc_height, putchr);
}
/*
* Move cursor to lower left corner of screen.
*/
public void
lower_left()
{
tputs(sc_lower_left, 1, putchr);
}
/*
* Ring the terminal bell.
*/
public void
bell()
{
if (quiet == VERY_QUIET)
vbell();
else
putchr('\7');
}
/*
* Output the "visual bell", if there is one.
*/
public void
vbell()
{
if (*sc_visual_bell == '\0')
return;
tputs(sc_visual_bell, sc_height, putchr);
}
/*
* Clear the screen.
*/
public void
clear()
{
tputs(sc_clear, sc_height, putchr);
}
/*
* Clear from the cursor to the end of the cursor's line.
* {{ This must not move the cursor. }}
*/
public void
clear_eol()
{
tputs(sc_eol_clear, 1, putchr);
}
/*
* Begin "standout" (bold, underline, or whatever).
*/
public void
so_enter()
{
tputs(sc_s_in, 1, putchr);
}
/*
* End "standout".
*/
public void
so_exit()
{
tputs(sc_s_out, 1, putchr);
}
/*
* Begin "underline" (hopefully real underlining,
* otherwise whatever the terminal provides).
*/
public void
ul_enter()
{
tputs(sc_u_in, 1, putchr);
}
/*
* End "underline".
*/
public void
ul_exit()
{
tputs(sc_u_out, 1, putchr);
}
/*
* Begin "bold"
*/
public void
bo_enter()
{
tputs(sc_b_in, 1, putchr);
}
/*
* End "bold".
*/
public void
bo_exit()
{
tputs(sc_b_out, 1, putchr);
}
/*
* Begin "blink"
*/
public void
bl_enter()
{
tputs(sc_bl_in, 1, putchr);
}
/*
* End "blink".
*/
public void
bl_exit()
{
tputs(sc_bl_out, 1, putchr);
}
/*
* Erase the character to the left of the cursor
* and move the cursor left.
*/
public void
backspace()
{
/*
* Try to erase the previous character by overstriking with a space.
*/
tputs(sc_backspace, 1, putchr);
putchr(' ');
tputs(sc_backspace, 1, putchr);
}
/*
* Output a plain backspace, without erasing the previous char.
*/
public void
putbs()
{
tputs(sc_backspace, 1, putchr);
}