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Fixed ancient bug in csh(1) "filec" implementation.

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We need not wait for a while any longer after pressing ESC or ^D.

Problem description:
If a user types characters during performing completion (ESC)
or listings (^D), the chars are inserted at weird position of
the command line.
This makes the command line unusable and irritates the user.
I noticed this on 386BSD(98), probably six years ago.

This change fixes the bug by implementing salvage of the characters.
The salvaged chars are added at the end of the command line.
An extra ioctl(FIONREAD) is required to work-around a glitch on
kernel tty driver.
This commit is contained in:
itohy 1998-12-26 02:11:39 +00:00
parent 468355c5f0
commit e50ba7ea8f
1 changed files with 77 additions and 8 deletions
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85
bin/csh/file.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: file.c,v 1.14 1998/07/28 02:47:20 mycroft Exp $ */
/* $NetBSD: file.c,v 1.15 1998/12/26 02:11:39 itohy Exp $ */
/*-
* Copyright (c) 1980, 1991, 1993
@ -38,7 +38,7 @@
#if 0
static char sccsid[] = "@(#)file.c 8.2 (Berkeley) 3/19/94";
#else
__RCSID("$NetBSD: file.c,v 1.14 1998/07/28 02:47:20 mycroft Exp $");
__RCSID("$NetBSD: file.c,v 1.15 1998/12/26 02:11:39 itohy Exp $");
#endif
#endif /* not lint */
@ -52,6 +52,7 @@ __RCSID("$NetBSD: file.c,v 1.14 1998/07/28 02:47:20 mycroft Exp $");
#include <pwd.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/tty.h>
#ifndef SHORT_STRINGS
#include <string.h>
#endif /* SHORT_STRINGS */
@ -88,7 +89,7 @@ typedef enum {
static void setup_tty __P((int));
static void back_to_col_1 __P((void));
static void pushback __P((Char *));
static int pushback __P((Char *));
static void catn __P((Char *, Char *, int));
static void copyn __P((Char *, Char *, int));
static Char filetype __P((Char *, Char *));
@ -163,7 +164,7 @@ back_to_col_1()
/*
* Push string contents back into tty queue
*/
static void
static int
pushback(string)
Char *string;
{
@ -171,6 +172,12 @@ pushback(string)
struct termios tty, tty_normal;
sigset_t sigset, osigset;
char c;
char buf[TTYHOG];
int nbuf, bufidx;
char svchars[TTYHOG];
int nsv = 0, onsv;
int len_str, i;
int retrycnt;
sigemptyset(&sigset);
(void) sigaddset(&sigset, SIGINT);
@ -178,12 +185,70 @@ pushback(string)
(void) tcgetattr(SHOUT, &tty);
tty_normal = tty;
tty.c_lflag &= ~(ECHOKE | ECHO | ECHOE | ECHOK | ECHONL | ECHOPRT | ECHOCTL);
/* FIONREAD works only in noncanonical mode. */
tty.c_lflag &= ~ICANON;
tty.c_cc[VMIN] = 0;
(void) tcsetattr(SHOUT, TCSADRAIN, &tty);
for (p = string; (c = *p) != '\0'; p++)
(void) ioctl(SHOUT, TIOCSTI, (ioctl_t) & c);
for (retrycnt = 5; ; retrycnt--) {
/*
* Push back characters.
*/
for (p = string; (c = *p) != '\0'; p++)
(void) ioctl(SHOUT, TIOCSTI, (ioctl_t) &c);
for (i = 0; i < nsv; i++)
(void) ioctl(SHOUT, TIOCSTI, (ioctl_t) &svchars[i]);
if (retrycnt == 0)
break; /* give up salvaging characters */
len_str = p - string;
if (ioctl(SHOUT, FIONREAD, (ioctl_t) &nbuf) ||
nbuf <= len_str + nsv || /* The string fit. */
nbuf > TTYHOG) /* For future binary compatibility
(and safety). */
break;
/*
* User has typed characters before the pushback finished.
* Salvage the characters.
*/
/* This read() should be in noncanonical mode. */
if (read(SHOUT, &buf, nbuf) != nbuf)
continue; /* hangup? */
onsv = nsv;
for (bufidx = 0, i = 0; bufidx < nbuf; bufidx++, i++) {
c = buf[bufidx];
if ((i < len_str) ? c != (char) string[i] :
(i < len_str + onsv) ? c != svchars[i - len_str] : 1) {
/* Salvage a character. */
if (nsv < (int) (sizeof svchars / sizeof svchars[0])) {
svchars[nsv++] = c;
i--; /* try this comparison with the next char */
} else
break; /* too much */
}
}
}
#if 1
/*
* XXX Is this a bug or a feature of kernel tty driver?
*
* FIONREAD in canonical mode does not return correct byte count
* in tty input queue, but this is required to avoid unwanted echo.
*/
tty.c_lflag |= ICANON;
(void) tcsetattr(SHOUT, TCSADRAIN, &tty);
(void) ioctl(SHOUT, FIONREAD, (ioctl_t) &i);
#endif
(void) tcsetattr(SHOUT, TCSADRAIN, &tty_normal);
(void) sigprocmask(SIG_SETMASK, &osigset, NULL);
return nsv;
}
/*
@ -670,9 +735,13 @@ tenex(inputline, inputline_size)
}
if (command == LIST) /* Always retype after a LIST */
should_retype = TRUE;
if (should_retype)
if (pushback(inputline))
should_retype = TRUE;
if (should_retype) {
if (command == RECOGNIZE)
(void) fputc('\n', cshout);
printprompt();
pushback(inputline);
}
if (should_retype)
retype();
}