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/*
* Copyright (c) 1988 Mark Nudleman
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)decode.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
/*
* Routines to decode user commands.
*
* This is all table driven.
* A command table is a sequence of command descriptors.
* Each command descriptor is a sequence of bytes with the following format:
* <c1><c2>...<cN><0><action>
* The characters c1,c2,...,cN are the command string; that is,
* the characters which the user must type.
* It is terminated by a null <0> byte.
* The byte after the null byte is the action code associated
* with the command string.
*
* The default commands are described by cmdtable.
*/
#include <sys/param.h>
#include <sys/file.h>
#include <stdio.h>
#include <less.h>
/*
* Command table is ordered roughly according to expected
* frequency of use, so the common commands are near the beginning.
*/
#define CONTROL(c) ((c)&037)
static char cmdtable[] = {
'\r',0, A_F_LINE,
'\n',0, A_F_LINE,
'j',0, A_F_LINE,
'k',0, A_B_LINE,
'd',0, A_F_SCROLL,
CONTROL('D'),0, A_F_SCROLL,
'u',0, A_B_SCROLL,
CONTROL('U'),0, A_B_SCROLL,
' ',0, A_F_SCREEN,
'f',0, A_F_SCREEN,
CONTROL('F'),0, A_F_SCREEN,
'b',0, A_B_SCREEN,
CONTROL('B'),0, A_B_SCREEN,
'R',0, A_FREPAINT,
'r',0, A_REPAINT,
CONTROL('L'),0, A_REPAINT,
'g',0, A_GOLINE,
'p',0, A_PERCENT,
'%',0, A_PERCENT,
'G',0, A_GOEND,
'0',0, A_DIGIT,
'1',0, A_DIGIT,
'2',0, A_DIGIT,
'3',0, A_DIGIT,
'4',0, A_DIGIT,
'5',0, A_DIGIT,
'6',0, A_DIGIT,
'7',0, A_DIGIT,
'8',0, A_DIGIT,
'9',0, A_DIGIT,
'=',0, A_STAT,
CONTROL('G'),0, A_STAT,
'/',0, A_F_SEARCH,
'?',0, A_B_SEARCH,
'n',0, A_AGAIN_SEARCH,
'm',0, A_SETMARK,
'\'',0, A_GOMARK,
'E',0, A_EXAMINE,
'N',0, A_NEXT_FILE,
':','n',0, A_NEXT_FILE,
'P',0, A_PREV_FILE,
':','p',0, A_PREV_FILE,
'v',0, A_VISUAL,
'h',0, A_HELP,
'q',0, A_QUIT,
':','q',0, A_QUIT,
':','t',0, A_TAGFILE,
':', 'a', 0, A_FILE_LIST,
'Z','Z',0, A_QUIT,
};
char *cmdendtable = cmdtable + sizeof(cmdtable);
#define MAX_CMDLEN 16
static char kbuf[MAX_CMDLEN+1];
static char *kp = kbuf;
/*
* Indicate that we're not in a prefix command
* by resetting the command buffer pointer.
*/
noprefix()
{
kp = kbuf;
}
/*
* Decode a command character and return the associated action.
*/
cmd_decode(c)
int c;
{
register int action = A_INVALID;
/*
* Append the new command character to the command string in kbuf.
*/
*kp++ = c;
*kp = '\0';
action = cmd_search(cmdtable, cmdendtable);
/* This is not a prefix character. */
if (action != A_PREFIX)
noprefix();
return(action);
}
/*
* Search a command table for the current command string (in kbuf).
*/
cmd_search(table, endtable)
char *table;
char *endtable;
{
register char *p, *q;
for (p = table, q = kbuf; p < endtable; p++, q++) {
if (*p == *q) {
/*
* Current characters match.
* If we're at the end of the string, we've found it.
* Return the action code, which is the character
* after the null at the end of the string
* in the command table.
*/
if (*p == '\0')
return(p[1]);
}
else if (*q == '\0') {
/*
* Hit the end of the user's command,
* but not the end of the string in the command table.
* The user's command is incomplete.
*/
return(A_PREFIX);
} else {
/*
* Not a match.
* Skip ahead to the next command in the
* command table, and reset the pointer
* to the user's command.
*/
while (*p++ != '\0');
q = kbuf-1;
}
}
/*
* No match found in the entire command table.
*/
return(A_INVALID);
}
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