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/* $NetBSD: db_input.c,v 1.6 1994/10/26 17:57:50 mycroft Exp $ */
/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <ddb/db_output.h>
/*
* Character input and editing.
*/
/*
* We don't track output position while editing input,
* since input always ends with a new-line. We just
* reset the line position at the end.
*/
char * db_lbuf_start; /* start of input line buffer */
char * db_lbuf_end; /* end of input line buffer */
char * db_lc; /* current character */
char * db_le; /* one past last character */
#define CTRL(c) ((c) & 0x1f)
#define isspace(c) ((c) == ' ' || (c) == '\t')
#define BLANK ' '
#define BACKUP '\b'
void
db_putstring(s, count)
char *s;
int count;
{
while (--count >= 0)
cnputc(*s++);
}
void
db_putnchars(c, count)
int c;
int count;
{
while (--count >= 0)
cnputc(c);
}
/*
* Delete N characters, forward or backward
*/
#define DEL_FWD 0
#define DEL_BWD 1
void
db_delete(n, bwd)
int n;
int bwd;
{
register char *p;
if (bwd) {
db_lc -= n;
db_putnchars(BACKUP, n);
}
for (p = db_lc; p < db_le-n; p++) {
*p = *(p+n);
cnputc(*p);
}
db_putnchars(BLANK, n);
db_putnchars(BACKUP, db_le - db_lc);
db_le -= n;
}
/* returns TRUE at end-of-line */
int
db_inputchar(c)
int c;
{
switch (c) {
case CTRL('b'):
/* back up one character */
if (db_lc > db_lbuf_start) {
cnputc(BACKUP);
db_lc--;
}
break;
case CTRL('f'):
/* forward one character */
if (db_lc < db_le) {
cnputc(*db_lc);
db_lc++;
}
break;
case CTRL('a'):
/* beginning of line */
while (db_lc > db_lbuf_start) {
cnputc(BACKUP);
db_lc--;
}
break;
case CTRL('e'):
/* end of line */
while (db_lc < db_le) {
cnputc(*db_lc);
db_lc++;
}
break;
case CTRL('h'):
case 0177:
/* erase previous character */
if (db_lc > db_lbuf_start)
db_delete(1, DEL_BWD);
break;
case CTRL('d'):
/* erase next character */
if (db_lc < db_le)
db_delete(1, DEL_FWD);
break;
case CTRL('k'):
/* delete to end of line */
if (db_lc < db_le)
db_delete(db_le - db_lc, DEL_FWD);
break;
case CTRL('t'):
/* twiddle last 2 characters */
if (db_lc >= db_lbuf_start + 2) {
c = db_lc[-2];
db_lc[-2] = db_lc[-1];
db_lc[-1] = c;
cnputc(BACKUP);
cnputc(BACKUP);
cnputc(db_lc[-2]);
cnputc(db_lc[-1]);
}
break;
case CTRL('r'):
db_putstring("^R\n", 3);
if (db_le > db_lbuf_start) {
db_putstring(db_lbuf_start, db_le - db_lbuf_start);
db_putnchars(BACKUP, db_le - db_lc);
}
break;
case '\n':
case '\r':
*db_le++ = c;
return (1);
default:
if (db_le == db_lbuf_end) {
cnputc('\007');
}
else if (c >= ' ' && c <= '~') {
register char *p;
for (p = db_le; p > db_lc; p--)
*p = *(p-1);
*db_lc++ = c;
db_le++;
cnputc(c);
db_putstring(db_lc, db_le - db_lc);
db_putnchars(BACKUP, db_le - db_lc);
}
break;
}
return (0);
}
int
db_readline(lstart, lsize)
char * lstart;
int lsize;
{
db_force_whitespace(); /* synch output position */
db_lbuf_start = lstart;
db_lbuf_end = lstart + lsize;
db_lc = lstart;
db_le = lstart;
while (!db_inputchar(cngetc()))
continue;
db_putchar('\n'); /* synch output position */
*db_le = 0;
return (db_le - db_lbuf_start);
}
void
db_check_interrupt()
{
register int c;
c = cnmaygetc();
switch (c) {
case -1: /* no character */
return;
case CTRL('c'):
db_error((char *)0);
/*NOTREACHED*/
case CTRL('s'):
do {
c = cnmaygetc();
if (c == CTRL('c')) {
db_error((char *)0);
/*NOTREACHED*/
}
} while (c != CTRL('q'));
break;
default:
/* drop on floor */
break;
}
}
cnmaygetc ()
{
return (-1);
}
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