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Almathera Ten Pack 2: CDPD 1
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Almathera Ten on Ten - Disc 2: CDPD 1.iso
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051-075
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074
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less
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screen.c
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C/C++ Source or Header
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1995-03-13
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11KB
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536 lines
/*
* 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
# ifndef amiga
# include <sgtty.h>
# endif
#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_visual_bell, /* Visual bell (flash screen) sequence */
*sc_backspace, /* Backspace cursor */
*sc_init, /* Startup terminal initialization */
*sc_deinit; /* Exit terminal de-intialization */
static int dumb;
static int hard;
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 ul_width, ue_width; /* Printing width of underline sequences */
public int so_width, se_width; /* Printing width of standout sequences */
/*
* 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;
char *tgetstr();
char *tgoto();
/*
* 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 be 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;
{
#ifdef amiga
extern int do_echo;
if (on)
do_echo = 0;
else
do_echo = 1;
erase_char = 8; /* ^H */
kill_char = 24; /* ^X */
#else
#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
#endif
}
static int couldnt = 0;
static void
cannot(s)
char *s;
{
if (know_dumb)
/*
* He knows he has a dumb terminal, so don't tell him.
*/
return;
printf("WARNING: terminal cannot \"%s\"\n", s);
couldnt = 1;
}
/*
* Get terminal capabilities via termcap.
*/
public void
get_term()
{
char termbuf[1024];
char *sp;
static char sbuf[150];
#ifdef amiga
/* I didn't want to port termcap for now, but there is a version
on fish #14 that someone might want to use */
sc_pad = ""; /* Pad string */
sc_home = "\x9b1;1H"; /* Cursor home */
sc_addline = "\x9bL"; /* Add line, scroll down following lines */
sc_lower_left = "\x9b23;1H";/* Cursor to last line, first column */
sc_move = ""; /* General cursor positioning */
sc_clear = "\f"; /* Clear screen */
sc_eol_clear = "\x9bK"; /* Clear to end of line */
sc_s_in = "\x9b0;32;43m"; /* Enter standout (highlighted) mode */
sc_s_out = "\x9bm"; /* Exit standout mode */
sc_u_in = "\x9b4m"; /* Enter underline mode */
sc_u_out = "\x9bm"; /* Exit underline mode */
sc_visual_bell = "\007"; /* Visual bell (flash screen) sequence */
sc_backspace = "\b"; /* Backspace cursor */
sc_init = ""; /* Startup terminal initialization */
sc_deinit = ""; /* Exit terminal de-intialization */
sc_height = 23;
sc_width = 77;
#else
char *getenv();
/*
* Find out what kind of terminal this is.
*/
if (tgetent(termbuf, getenv("TERM")) <= 0)
dumb = 1;
/*
* Get size of the screen.
*/
if (dumb || (sc_height = tgetnum("li")) < 0 || tgetflag("hc"))
{
/* Oh no, this is a hardcopy terminal. */
hard = 1;
sc_height = 24;
}
if (dumb || (sc_width = tgetnum("co")) < 0)
sc_width = 80;
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, and the end underline sequence.
*/
if ((ul_width = tgetnum("sg")) < 0)
ul_width = 0;
so_width = se_width = ue_width = ul_width;
/*
* Get various string-valued capabilities.
*/
sp = sbuf;
sc_pad = (dumb) ? NULL : tgetstr("pc", &sp);
if (sc_pad != NULL)
PC = *sc_pad;
sc_init = (dumb) ? NULL : tgetstr("ti", &sp);
if (sc_init == NULL)
sc_init = "";
sc_deinit= (dumb) ? NULL : tgetstr("te", &sp);
if (sc_deinit == NULL)
sc_deinit = "";
sc_eol_clear = (dumb) ? NULL : tgetstr("ce", &sp);
if (hard || sc_eol_clear == NULL || *sc_eol_clear == '\0')
{
cannot("clear to end of line");
sc_eol_clear = "";
}
sc_clear = (dumb) ? NULL : tgetstr("cl", &sp);
if (hard || sc_clear == NULL || *sc_clear == '\0')
{
cannot("clear screen");
sc_clear = "\n\n";
}
sc_move = (dumb) ? NULL : 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 = (dumb) ? NULL : tgetstr("so", &sp);
if (hard || sc_s_in == NULL)
sc_s_in = "";
sc_s_out = (dumb) ? NULL : tgetstr("se", &sp);
if (hard || sc_s_out == NULL)
sc_s_out = "";
sc_u_in = (dumb) ? NULL : tgetstr("us", &sp);
if (hard || sc_u_in == NULL)
sc_u_in = sc_s_in;
sc_u_out = (dumb) ? NULL : tgetstr("ue", &sp);
if (hard || sc_u_out == NULL)
sc_u_out = sc_s_out;
sc_visual_bell = (dumb) ? NULL : tgetstr("vb", &sp);
if (hard || sc_visual_bell == NULL)
sc_visual_bell = "";
sc_home = (dumb) ? NULL : tgetstr("ho", &sp);
if (hard || sc_home == NULL || *sc_home == '\0')
{
if (*sc_move == '\0')
{
cannot("home cursor");
/*
* This last resort for sc_home is supposed to
* be an up-arrow suggesting moving to the
* top of the "virtual screen". (The one in
* your imagination as you try to use this on
* a hard copy terminal.)
*/
sc_home = "|\b^";
} else
{
/*
* No "home" string,
* but we can use "move(0,0)".
*/
strcpy(sp, tgoto(sc_move, 0, 0));
sc_home = sp;
sp += strlen(sp) + 1;
}
}
sc_lower_left = (dumb) ? NULL : tgetstr("ll", &sp);
if (hard || sc_lower_left == NULL || *sc_lower_left == '\0')
{
if (*sc_move == '\0')
{
cannot("move cursor to lower left of screen");
sc_lower_left = "\r";
} else
{
/*
* No "lower-left" string,
* but we can use "move(0,last-line)".
*/
strcpy(sp, tgoto(sc_move, 0, sc_height-1));
sc_lower_left = sp;
sp += strlen(sp) + 1;
}
}
/*
* To add a line at top of screen and scroll the display down,
* we use "al" (add line) or "sr" (scroll reverse).
*/
if (dumb)
sc_addline = NULL;
else if ((sc_addline = tgetstr("al", &sp)) == NULL ||
*sc_addline == '\0')
sc_addline = tgetstr("sr", &sp);
if (hard || sc_addline == NULL || *sc_addline == '\0')
{
cannot("scroll backwards");
sc_addline = "";
/* Force repaint on any backward movement */
back_scroll = 0;
}
if (dumb || tgetflag("bs"))
sc_backspace = "\b";
else
{
sc_backspace = tgetstr("bc", &sp);
if (sc_backspace == NULL || *sc_backspace == '\0')
sc_backspace = "\b";
}
if (couldnt)
/* Give him time to read all the "cannot" messages. */
error("");
#endif
}
/*
* Below are the functions which perform all the
* terminal-specific screen manipulation.
*/
/*
* Initialize terminal
*/
public void
init()
{
tputs(sc_init, sc_height, putc);
}
/*
* Deinitialize terminal
*/
public void
deinit()
{
tputs(sc_deinit, sc_height, putc);
}
/*
* Home cursor (move to upper left corner of screen).
*/
public void
home()
{
tputs(sc_home, 1, putc);
}
/*
* Add a blank line (called with cursor at home).
* Should scroll the display down.
*/
public void
add_line()
{
tputs(sc_addline, sc_height, putc);
}
/*
* Move cursor to lower left corner of screen.
*/
public void
lower_left()
{
tputs(sc_lower_left, 1, putc);
}
/*
* Ring the terminal bell.
*/
public void
bell()
{
if (quiet == VERY_QUIET)
vbell();
else
putc('\7');
}
/*
* Output the "visual bell", if there is one.
*/
public void
vbell()
{
if (*sc_visual_bell == '\0')
return;
tputs(sc_visual_bell, sc_height, putc);
}
/*
* Clear the screen.
*/
public void
clear()
{
tputs(sc_clear, sc_height, putc);
}
/*
* 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, putc);
}
/*
* Begin "standout" (bold, underline, or whatever).
*/
public void
so_enter()
{
tputs(sc_s_in, 1, putc);
}
/*
* End "standout".
*/
public void
so_exit()
{
tputs(sc_s_out, 1, putc);
}
/*
* Begin "underline" (hopefully real underlining,
* otherwise whatever the terminal provides).
*/
public void
ul_enter()
{
tputs(sc_u_in, 1, putc);
}
/*
* End "underline".
*/
public void
ul_exit()
{
tputs(sc_u_out, 1, putc);
}
/*
* 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, putc);
putc(' ');
tputs(sc_backspace, 1, putc);
}
/*
* Output a plain backspace, without erasing the previous char.
*/
public void
putbs()
{
tputs(sc_backspace, 1, putc);
}