freebsd-dev/contrib/nvi/cl/cl_screen.c
Robert Watson 09333c6166 o nvi failed to correctly handle EINTR returned from tcsetattr(), exiting
instead of recovering, which happens in particular during a rapid series
  of SIGWINCH's.  This change forces nvi to loop on the call in the event
  that the call is interrupted.

Interestingly, I submitted this bug report in 1998, and a solution was
posted shortly thereafter by Matthias Buelow; it's been sitting in the
PR database ever since.

Note: this takes this file off the vendor branch.  If and when we find
a vendor for this code, the fix should be given back to them.

PR:		bin/8438
Submitted by:	Matthias Buelow <mkb@altair.mayn.de>
MFC after:	1 month
2001-11-09 02:23:05 +00:00

588 lines
14 KiB
C

/*-
* Copyright (c) 1993, 1994
* The Regents of the University of California. All rights reserved.
* Copyright (c) 1993, 1994, 1995, 1996
* Keith Bostic. All rights reserved.
*
* See the LICENSE file for redistribution information.
*
* $FreeBSD$
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)cl_screen.c 10.49 (Berkeley) 9/24/96";
#endif /* not lint */
#include <sys/types.h>
#include <sys/queue.h>
#include <bitstring.h>
#include <curses.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include "../common/common.h"
#include "cl.h"
static int cl_ex_end __P((GS *));
static int cl_ex_init __P((SCR *));
static void cl_freecap __P((CL_PRIVATE *));
static int cl_vi_end __P((GS *));
static int cl_vi_init __P((SCR *));
static int cl_putenv __P((char *, char *, u_long));
/*
* cl_screen --
* Switch screen types.
*
* PUBLIC: int cl_screen __P((SCR *, u_int32_t));
*/
int
cl_screen(sp, flags)
SCR *sp;
u_int32_t flags;
{
CL_PRIVATE *clp;
GS *gp;
gp = sp->gp;
clp = CLP(sp);
/* See if the current information is incorrect. */
if (F_ISSET(gp, G_SRESTART)) {
if (cl_quit(gp))
return (1);
F_CLR(gp, G_SRESTART);
}
/* See if we're already in the right mode. */
if (LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX) ||
LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI))
return (0);
/*
* Fake leaving ex mode.
*
* We don't actually exit ex or vi mode unless forced (e.g. by a window
* size change). This is because many curses implementations can't be
* called twice in a single program. Plus, it's faster. If the editor
* "leaves" vi to enter ex, when it exits ex we'll just fall back into
* vi.
*/
if (F_ISSET(sp, SC_SCR_EX))
F_CLR(sp, SC_SCR_EX);
/*
* Fake leaving vi mode.
*
* Clear out the rest of the screen if we're in the middle of a split
* screen. Move to the last line in the current screen -- this makes
* terminal scrolling happen naturally. Note: *don't* move past the
* end of the screen, as there are ex commands (e.g., :read ! cat file)
* that don't want to. Don't clear the info line, its contents may be
* valid, e.g. :file|append.
*/
if (F_ISSET(sp, SC_SCR_VI)) {
F_CLR(sp, SC_SCR_VI);
if (sp->q.cqe_next != (void *)&gp->dq) {
(void)move(RLNO(sp, sp->rows), 0);
clrtobot();
}
(void)move(RLNO(sp, sp->rows) - 1, 0);
refresh();
}
/* Enter the requested mode. */
if (LF_ISSET(SC_EX)) {
if (cl_ex_init(sp))
return (1);
F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
/*
* If doing an ex screen for ex mode, move to the last line
* on the screen.
*/
if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
tputs(tgoto(clp->cup,
0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
} else {
if (cl_vi_init(sp))
return (1);
F_CLR(clp, CL_IN_EX);
F_SET(clp, CL_SCR_VI_INIT);
}
return (0);
}
/*
* cl_quit --
* Shutdown the screens.
*
* PUBLIC: int cl_quit __P((GS *));
*/
int
cl_quit(gp)
GS *gp;
{
CL_PRIVATE *clp;
int rval;
rval = 0;
clp = GCLP(gp);
/*
* If we weren't really running, ignore it. This happens if the
* screen changes size before we've called curses.
*/
if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
return (0);
/* Clean up the terminal mappings. */
if (cl_term_end(gp))
rval = 1;
/* Really leave vi mode. */
if (F_ISSET(clp, CL_STDIN_TTY) &&
F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
rval = 1;
/* Really leave ex mode. */
if (F_ISSET(clp, CL_STDIN_TTY) &&
F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
rval = 1;
/*
* If we were running ex when we quit, or we're using an implementation
* of curses where endwin() doesn't get this right, restore the original
* terminal modes.
*
* XXX
* We always do this because it's too hard to figure out what curses
* implementations get it wrong. It may discard type-ahead characters
* from the tty queue.
*/
(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
return (rval);
}
/*
* cl_vi_init --
* Initialize the curses vi screen.
*/
static int
cl_vi_init(sp)
SCR *sp;
{
CL_PRIVATE *clp;
GS *gp;
char *o_cols, *o_lines, *o_term, *ttype;
gp = sp->gp;
clp = CLP(sp);
/* If already initialized, just set the terminal modes. */
if (F_ISSET(clp, CL_SCR_VI_INIT))
goto fast;
/* Curses vi always reads from (and writes to) a terminal. */
if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
msgq(sp, M_ERR,
"016|Vi's standard input and output must be a terminal");
return (1);
}
/* We'll need a terminal type. */
if (opts_empty(sp, O_TERM, 0))
return (1);
ttype = O_STR(sp, O_TERM);
/*
* XXX
* Changing the row/column and terminal values is done by putting them
* into the environment, which is then read by curses. What this loses
* in ugliness, it makes up for in stupidity. We can't simply put the
* values into the environment ourselves, because in the presence of a
* kernel mechanism for returning the window size, entering values into
* the environment will screw up future screen resizing events, e.g. if
* the user enters a :shell command and then resizes their window. So,
* if they weren't already in the environment, we make sure to delete
* them immediately after setting them.
*
* XXX
* Putting the TERM variable into the environment is necessary, even
* though we're using newterm() here. We may be using initscr() as
* the underlying function.
*/
o_term = getenv("TERM");
cl_putenv("TERM", ttype, 0);
o_lines = getenv("LINES");
cl_putenv("LINES", NULL, (u_long)O_VAL(sp, O_LINES));
o_cols = getenv("COLUMNS");
cl_putenv("COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
/*
* We don't care about the SCREEN reference returned by newterm, we
* never have more than one SCREEN at a time.
*
* XXX
* The SunOS initscr() can't be called twice. Don't even think about
* using it. It fails in subtle ways (e.g. select(2) on fileno(stdin)
* stops working). (The SVID notes that applications should only call
* initscr() once.)
*
* XXX
* The HP/UX newterm doesn't support the NULL first argument, so we
* have to specify the terminal type.
*/
errno = 0;
if (newterm(ttype, stdout, stdin) == NULL) {
if (errno)
msgq(sp, M_SYSERR, "%s", ttype);
else
msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
return (1);
}
if (o_term == NULL)
unsetenv("TERM");
if (o_lines == NULL)
unsetenv("LINES");
if (o_cols == NULL)
unsetenv("COLUMNS");
/*
* XXX
* Someone got let out alone without adult supervision -- the SunOS
* newterm resets the signal handlers. There's a race, but it's not
* worth closing.
*/
(void)sig_init(sp->gp, sp);
/*
* We use raw mode. What we want is 8-bit clean, however, signals
* and flow control should continue to work. Admittedly, it sounds
* like cbreak, but it isn't. Using cbreak() can get you additional
* things like IEXTEN, which turns on flags like DISCARD and LNEXT.
*
* !!!
* If raw isn't turning off echo and newlines, something's wrong.
* However, it shouldn't hurt.
*/
noecho(); /* No character echo. */
nonl(); /* No CR/NL translation. */
raw(); /* 8-bit clean. */
idlok(stdscr, 1); /* Use hardware insert/delete line. */
/* Put the cursor keys into application mode. */
(void)keypad(stdscr, TRUE);
/*
* XXX
* The screen TI sequence just got sent. See the comment in
* cl_funcs.c:cl_attr().
*/
clp->ti_te = TI_SENT;
/*
* XXX
* Historic implementations of curses handled SIGTSTP signals
* in one of three ways. They either:
*
* 1: Set their own handler, regardless.
* 2: Did not set a handler if a handler was already installed.
* 3: Set their own handler, but then called any previously set
* handler after completing their own cleanup.
*
* We don't try and figure out which behavior is in place, we force
* it to SIG_DFL after initializing the curses interface, which means
* that curses isn't going to take the signal. Since curses isn't
* reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
* we're doing The Right Thing.
*/
(void)signal(SIGTSTP, SIG_DFL);
/*
* If flow control was on, turn it back on. Turn signals on. ISIG
* turns on VINTR, VQUIT, VDSUSP and VSUSP. The main curses code
* already installed a handler for VINTR. We're going to disable the
* other three.
*
* XXX
* We want to use ^Y as a vi scrolling command. If the user has the
* DSUSP character set to ^Y (common practice) clean it up. As it's
* equally possible that the user has VDSUSP set to 'a', we disable
* it regardless. It doesn't make much sense to suspend vi at read,
* so I don't think anyone will care. Alternatively, we could look
* it up in the table of legal command characters and turn it off if
* it matches one. VDSUSP wasn't in POSIX 1003.1-1990, so we test for
* it.
*
* XXX
* We don't check to see if the user had signals enabled originally.
* If they didn't, it's unclear what we're supposed to do here, but
* it's also pretty unlikely.
*/
if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
msgq(sp, M_SYSERR, "tcgetattr");
goto err;
}
if (clp->orig.c_iflag & IXON)
clp->vi_enter.c_iflag |= IXON;
if (clp->orig.c_iflag & IXOFF)
clp->vi_enter.c_iflag |= IXOFF;
clp->vi_enter.c_lflag |= ISIG;
#ifdef VDSUSP
clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
#endif
clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
/*
* XXX
* OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
* characters when curses switches into raw mode. It should be OK
* to do it explicitly for everyone.
*/
#ifdef VDISCARD
clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
#endif
#ifdef VLNEXT
clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
#endif
#ifdef VSTATUS
clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
#endif
/* Initialize terminal based information. */
if (cl_term_init(sp))
goto err;
fast: /* Set the terminal modes. */
if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
if (errno == EINTR)
goto fast;
msgq(sp, M_SYSERR, "tcsetattr");
err: (void)cl_vi_end(sp->gp);
return (1);
}
return (0);
}
/*
* cl_vi_end --
* Shutdown the vi screen.
*/
static int
cl_vi_end(gp)
GS *gp;
{
CL_PRIVATE *clp;
clp = GCLP(gp);
/* Restore the cursor keys to normal mode. */
(void)keypad(stdscr, FALSE);
/*
* If we were running vi when we quit, scroll the screen up a single
* line so we don't lose any information.
*
* Move to the bottom of the window (some endwin implementations don't
* do this for you).
*/
if (!F_ISSET(clp, CL_IN_EX)) {
(void)move(0, 0);
(void)deleteln();
(void)move(LINES - 1, 0);
(void)refresh();
}
cl_freecap(clp);
/* End curses window. */
(void)endwin();
/*
* XXX
* The screen TE sequence just got sent. See the comment in
* cl_funcs.c:cl_attr().
*/
clp->ti_te = TE_SENT;
return (0);
}
/*
* cl_ex_init --
* Initialize the ex screen.
*/
static int
cl_ex_init(sp)
SCR *sp;
{
CL_PRIVATE *clp;
clp = CLP(sp);
/* If already initialized, just set the terminal modes. */
if (F_ISSET(clp, CL_SCR_EX_INIT))
goto fast;
/* If not reading from a file, we're done. */
if (!F_ISSET(clp, CL_STDIN_TTY))
return (0);
/* Get the ex termcap/terminfo strings. */
(void)cl_getcap(sp, "cup", &clp->cup);
(void)cl_getcap(sp, "smso", &clp->smso);
(void)cl_getcap(sp, "rmso", &clp->rmso);
(void)cl_getcap(sp, "el", &clp->el);
(void)cl_getcap(sp, "cuu1", &clp->cuu1);
/* Enter_standout_mode and exit_standout_mode are paired. */
if (clp->smso == NULL || clp->rmso == NULL) {
if (clp->smso != NULL) {
free(clp->smso);
clp->smso = NULL;
}
if (clp->rmso != NULL) {
free(clp->rmso);
clp->rmso = NULL;
}
}
/*
* Turn on canonical mode, with normal input and output processing.
* Start with the original terminal settings as the user probably
* had them (including any local extensions) set correctly for the
* current terminal.
*
* !!!
* We can't get everything that we need portably; for example, ONLCR,
* mapping <newline> to <carriage-return> on output isn't required
* by POSIX 1003.1b-1993. If this turns out to be a problem, then
* we'll either have to play some games on the mapping, or we'll have
* to make all ex printf's output \r\n instead of \n.
*/
clp->ex_enter = clp->orig;
clp->ex_enter.c_lflag |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
#ifdef ECHOCTL
clp->ex_enter.c_lflag |= ECHOCTL;
#endif
#ifdef ECHOKE
clp->ex_enter.c_lflag |= ECHOKE;
#endif
clp->ex_enter.c_iflag |= ICRNL;
clp->ex_enter.c_oflag |= OPOST;
#ifdef ONLCR
clp->ex_enter.c_oflag |= ONLCR;
#endif
fast: if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
if (errno == EINTR)
goto fast;
msgq(sp, M_SYSERR, "tcsetattr");
return (1);
}
return (0);
}
/*
* cl_ex_end --
* Shutdown the ex screen.
*/
static int
cl_ex_end(gp)
GS *gp;
{
CL_PRIVATE *clp;
clp = GCLP(gp);
cl_freecap(clp);
return (0);
}
/*
* cl_getcap --
* Retrieve termcap/terminfo strings.
*
* PUBLIC: int cl_getcap __P((SCR *, char *, char **));
*/
int
cl_getcap(sp, name, elementp)
SCR *sp;
char *name, **elementp;
{
size_t len;
char *t;
if ((t = tigetstr(name)) != NULL &&
t != (char *)-1 && (len = strlen(t)) != 0) {
MALLOC_RET(sp, *elementp, char *, len + 1);
memmove(*elementp, t, len + 1);
}
return (0);
}
/*
* cl_freecap --
* Free any allocated termcap/terminfo strings.
*/
static void
cl_freecap(clp)
CL_PRIVATE *clp;
{
if (clp->el != NULL) {
free(clp->el);
clp->el = NULL;
}
if (clp->cup != NULL) {
free(clp->cup);
clp->cup = NULL;
}
if (clp->cuu1 != NULL) {
free(clp->cuu1);
clp->cuu1 = NULL;
}
if (clp->rmso != NULL) {
free(clp->rmso);
clp->rmso = NULL;
}
if (clp->smso != NULL) {
free(clp->smso);
clp->smso = NULL;
}
}
/*
* cl_putenv --
* Put a value into the environment.
*/
static int
cl_putenv(name, str, value)
char *name, *str;
u_long value;
{
char buf[40];
if (str == NULL) {
(void)snprintf(buf, sizeof(buf), "%lu", value);
return (setenv(name, buf, 1));
} else
return (setenv(name, str, 1));
}