freebsd-nq/sys/ddb/db_variables.c
John Baldwin d39d4a6e64 - Change the ddb paging "support" to use a variable (db_lines_per_page) to
control the number of lines per page rather than a constant.  The variable
  can be examined and changed in ddb as '$lines'.  Setting the variable to
  0 will effectively turn off paging.
- Change db_putchar() to force out pending whitespace before outputting
  newlines and carriage returns so that one can rub out content on the
  current line via '\r     \r' type strings.
- Change the simple pager to rub out the --More-- prompt explicitly when
  the routine exits.
- Add some aliases to the simple pager to make it more compatible with
  more(1): 'e' and 'j' do a single line.  'd' does half a page, and
  'f' does a full page.

MFC after:	1 month
Inspired by:	kris
2004-11-01 22:15:15 +00:00

154 lines
3.3 KiB
C

/*
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#include <ddb/db_variables.h>
static int db_find_variable(struct db_variable **varp);
static struct db_variable db_vars[] = {
{ "radix", &db_radix, FCN_NULL },
{ "maxoff", &db_maxoff, FCN_NULL },
{ "maxwidth", &db_max_width, FCN_NULL },
{ "tabstops", &db_tab_stop_width, FCN_NULL },
{ "lines", &db_lines_per_page, FCN_NULL },
};
static struct db_variable *db_evars =
db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
static int
db_find_variable(struct db_variable **varp)
{
struct db_variable *vp;
int t;
t = db_read_token();
if (t == tIDENT) {
for (vp = db_vars; vp < db_evars; vp++) {
if (!strcmp(db_tok_string, vp->name)) {
*varp = vp;
return (1);
}
}
for (vp = db_regs; vp < db_eregs; vp++) {
if (!strcmp(db_tok_string, vp->name)) {
*varp = vp;
return (1);
}
}
}
db_error("Unknown variable\n");
return (0);
}
int
db_get_variable(db_expr_t *valuep)
{
struct db_variable *vp;
if (!db_find_variable(&vp))
return (0);
return (db_read_variable(vp, valuep));
}
int
db_set_variable(db_expr_t value)
{
struct db_variable *vp;
if (!db_find_variable(&vp))
return (0);
return (db_write_variable(vp, value));
}
int
db_read_variable(struct db_variable *vp, db_expr_t *valuep)
{
db_varfcn_t *func = vp->fcn;
if (func == FCN_NULL) {
*valuep = *(vp->valuep);
return (1);
}
return ((*func)(vp, valuep, DB_VAR_GET));
}
int
db_write_variable(struct db_variable *vp, db_expr_t value)
{
db_varfcn_t *func = vp->fcn;
if (func == FCN_NULL) {
*(vp->valuep) = value;
return (1);
}
return ((*func)(vp, &value, DB_VAR_SET));
}
void
db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
{
struct db_variable *vp;
db_expr_t value;
int t;
t = db_read_token();
if (t != tDOLLAR) {
db_error("Unknown variable\n");
return;
}
if (!db_find_variable(&vp)) {
db_error("Unknown variable\n");
return;
}
t = db_read_token();
if (t != tEQ)
db_unread_token(t);
if (!db_expression(&value)) {
db_error("No value\n");
return;
}
if (db_read_token() != tEOL)
db_error("?\n");
db_write_variable(vp, value);
}