usr.sbin/keymap/lib/keycap.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Parts Copyright 1992 by Holger Veit
 *
 * 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.
 *
 * This code has been derived from the PRINTCAP source code that is part
 * of 386bsd which underlies the above Copyright. Changes have been made
 * by Holger Veit (-hv-)
 *
 * 29/07/92 -hv- copied and adapted from printcap common_source
 *
 * -hv-: Hey, after gettytab, termcap and printcap this is the fourth time,
 * that this code has been adapted. Now, we should perhaps think about
 * a universal capabilities library which unites all four and allows different
 * data bases to be checked with a unified interface. This must be
 * documented of course in great detail. Any volunteers?
 *
 * "Suddenly, it was so quiet, one could almost hear a byte drop to
 * the floor..."
 *                      "1000 methods to get rid of hackers"
 *                              by H. Veit, to appear RSN :-)
 */

#ifndef lint
static char sccsid[] = "@(#)keycap.c    1.0 (Contributed to 386bsd) 7/29/92";
#endif /* not lint */

#include <ctype.h>
#include <stdio.h>
#include "pathnames.h"

#ifndef BUFSIZ
#define BUFSIZ  1024
#endif
#define MAXHOP  32      /* max number of tc= indirections */

/*
 * keycap - routines for dealing with the keyboard capability data base
 *
 * BUG:         Should use a "last" pointer in tbuf, so that searching
 *              for capabilities alphabetically would not be a n**2/2
 *              process when large numbers of capabilities are given.
 * Note:        If we add a last pointer now we will screw up the
 *              tc capability. We really should compile termcap.
 *
 * Essentially all the work here is scanning and decoding escapes
 * in string capabilities.  We don't use stdio because the editor
 * doesn't, and because living w/o it is not hard.
 */

#define KEYCAP

#ifdef KEYCAP
#define tgetent kgetent
#define tskip   kskip
#define tgetstr kgetstr
#define tdecode kdecode
#define tgetnum kgetnum
#define tgetflag kgetflag
#define tdecode kdecode
#define tnchktc knchktc
#define tnamatch knamatch
#define V6
#endif

static  FILE *pfp = NULL;       /* keycap data base file pointer */
static  char *tbuf;
static  int hopcount;           /* detect infinite loops in keycap, init 0 */
static char     *tskip();
char    *tgetstr();
static char     *tdecode();
char    *getenv();

/*
 *
 * -hv- added to understand capability names longer than 2 chars
 *      which is very important if we do not want to crypt the key codes
 */
static char *nmatch(id,cstr)
        char *id,*cstr;
{
        register n = strlen(id);
        register char *c = cstr+n;

        if (strncmp(id,cstr,n)==0 &&
            (*c==':' || *c=='|' || *c=='=' || *c=='#' || *c=='@')) {
                return c;
        }
        return 0;
}

#ifdef NOTUSED
/*
 * Similar to tgetent except it returns the next entry instead of
 * doing a lookup.
 */
getprent(bp)
        register char *bp;
{
        register int c, skip = 0;

        if (pfp == NULL && (pfp = fopen(_PATH_KEYCAP, "r")) == NULL)
                return(-1);
        tbuf = bp;
        for (;;) {
                switch (c = getc(pfp)) {
                case EOF:
                        fclose(pfp);
                        pfp = NULL;
                        return(0);
                case '\n':
                        if (bp == tbuf) {
                                skip = 0;
                                continue;
                        }
                        if (bp[-1] == '\\') {
                                bp--;
                                continue;
                        }
                        *bp = '\0';
                        return(1);
                case '#':
                        if (bp == tbuf)
                                skip++;
                default:
                        if (skip)
                                continue;
                        if (bp >= tbuf+BUFSIZ) {
                                write(2, "Keycap entry too long\n", 23);
                                *bp = '\0';
                                return(1);
                        }
                        *bp++ = c;
                }
        }
}

endprent()
{
        if (pfp != NULL)
                fclose(pfp);
}
#endif

/*
 * Get an entry for keyboard name in buffer bp,
 * from the keycap file.  Parse is very rudimentary;
 * we just notice escaped newlines.
 *
 */
tgetent(bp, name)
        char *bp, *name;
{

        register char *cp;
        register int c;
        register int i = 0, cnt = 0;
        char ibuf[BUFSIZ];
        char *cp2;
        int tf;

        tbuf = bp;
        tf = 0;

        cp = getenv("KEYCAP");
        /*
         * KEYCAP can have one of two things in it. It can be the
         * name of a file to use instead of /usr/share/misc/keycap. In this
         * case it better start with a "/". Or it can be an entry to
         * use so we don't have to read the file. In this case it
         * has to already have the newlines crunched out.
         */
        if (cp && *cp) {
                if (*cp!='/') {
                        cp2 = getenv("KEYBOARD");
                        if (cp2==(char *) 0 || strcmp(name,cp2)==0) {
                                strcpy(bp,cp);
                                return(tnchktc());
                        } else {
                                tf = open(_PATH_KEYCAP, 0);
                        }
                } else
                        tf = open(cp, 0);
        }
        if (tf==0)
                tf = open(_PATH_KEYCAP, 0);

        if (tf < 0)
                return (-1);
        for (;;) {
                cp = bp;
                for (;;) {
                        if (i == cnt) {
                                cnt = read(tf, ibuf, BUFSIZ);
                                if (cnt <= 0) {
                                        close(tf);
                                        return (0);
                                }
                                i = 0;
                        }
                        c = ibuf[i++];
                        if (c == '\n') {
                                if (cp > bp && cp[-1] == '\\'){
                                        cp--;
                                        continue;
                                }
                                break;
                        }
                        if (cp >= bp+BUFSIZ) {
                                write(2,"Keycap entry too long\n", 22);
                                break;
                        } else
                                *cp++ = c;
                }
                *cp = 0;

                /*
                 * The real work for the match.
                 */
                if (tnamatch(name)) {
                        close(tf);
                        return(tnchktc());
                }
        }
}

/*
 * tnchktc: check the last entry, see if it's tc=xxx. If so,
 * recursively find xxx and append that entry (minus the names)
 * to take the place of the tc=xxx entry. This allows keycap
 * entries to say "like an HP2621 but doesn't turn on the labels".
 * Note that this works because of the left to right scan.
 */
tnchktc()
{
        register char *p, *q;
        char tcname[16];        /* name of similar keyboard */
        char tcbuf[BUFSIZ];
        char *holdtbuf = tbuf;
        int l;

        p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
        while (*--p != ':')
                if (p<tbuf) {
                        write(2, "Bad keycap entry\n", 17);
                        return (0);
                }
        p++;
        /* p now points to beginning of last field */
        if (p[0] != 't' || p[1] != 'c')
                return(1);
        strcpy(tcname,p+3);
        q = tcname;
        while (q && *q != ':')
                q++;
        *q = 0;
        if (++hopcount > MAXHOP) {
                write(2, "Infinite tc= loop\n", 18);
                return (0);
        }
        if (tgetent(tcbuf, tcname) != 1)
                return(0);
        for (q=tcbuf; *q != ':'; q++)
                ;
        l = p - holdtbuf + strlen(q);
        if (l > BUFSIZ) {
                write(2, "Keycap entry too long\n", 22);
                q[BUFSIZ - (p-tbuf)] = 0;
        }
        strcpy(p, q+1);
        tbuf = holdtbuf;
        return(1);
}

/*
 * Tnamatch deals with name matching.  The first field of the keycap
 * entry is a sequence of names separated by |'s, so we compare
 * against each such name.  The normal : terminator after the last
 * name (before the first field) stops us.
 */
tnamatch(np)
        char *np;
{
        register char *Np, *Bp;

        Bp = tbuf;
        if (*Bp == '#' || *Bp == 0)
                return(0);
        for (;;) {
                for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
                        continue;
                if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
                        return (1);
                while (*Bp && *Bp != ':' && *Bp != '|')
                        Bp++;
                if (*Bp == 0 || *Bp == ':')
                        return (0);
                Bp++;
        }
}

/*
 * Skip to the next field.  Notice that this is very dumb, not
 * knowing about \: escapes or any such.  If necessary, :'s can be put
 * into the keycap file in octal.
 */
static char *
tskip(bp)
        register char *bp;
{

        while (*bp && *bp != ':')
                bp++;
        if (*bp == ':')
                bp++;
        return (bp);
}

/*
 * Return the (numeric) option id.
 * Numeric options look like
 *      li#80
 * i.e. the option string is separated from the numeric value by
 * a # character.  If the option is not found we return -1.
 * Note that we handle octal numbers beginning with 0.
 */
tgetnum(id)
        char *id;
{
        register int i, base;
        register char *bp = tbuf,*xp;

        for (;;) {
                bp = tskip(bp);
                if (*bp == 0)
                        return (-1);
                if ((xp=nmatch(id,bp)) == 0)
                        continue;
                bp = xp;        /* we have an entry */
                if (*bp == '@')
                        return(-1);
                if (*bp != '#')
                        continue;
                bp++;
                base = 10;
                if (*bp == '0')
                        base = 8;
                i = 0;
                while (isdigit(*bp))
                        i *= base, i += *bp++ - '0';
                return (i);
        }
}

/*
 * Handle a flag option.
 * Flag options are given "naked", i.e. followed by a : or the end
 * of the buffer.  Return 1 if we find the option, or 0 if it is
 * not given.
 */
tgetflag(id)
        char *id;
{
        register char *bp = tbuf,*xp;

        for (;;) {
                bp = tskip(bp);
                if (!*bp)
                        return (0);
                if ((xp=nmatch(id,bp)) != 0) {
                        bp = xp;
                        if (!*bp || *bp == ':')
                                return (1);
                        else if (*bp == '@')
                                return(0);
                }
        }
        /*NOTREACHED*/
}

/*
 * Get a string valued option.
 * These are given as
 *      cl=^Z
 * Much decoding is done on the strings, and the strings are
 * placed in area, which is a ref parameter which is updated.
 * No checking on area overflow.
 */
char *
tgetstr(id, area)
        char *id, **area;
{
        register char *bp = tbuf,*xp;

        for (;;) {
                bp = tskip(bp);
                if (!*bp)
                        return (0);
                if ((xp = nmatch(id,bp)) == 0)
                        continue;
                bp = xp;
                if (*bp == '@')
                        return(0);
                if (*bp != '=')
                        continue;
                bp++;
                return (tdecode(bp, area));
        }
}

/*
 * Tdecode does the grung work to decode the
 * string capability escapes.
 */
static char *
tdecode(str, area)
        register char *str;
        char **area;
{
        register char *cp;
        register int c;
        register char *dp;
        int i;

        cp = *area;
        while ((c = *str++) && c != ':') {
                switch (c) {

                case '^':
                        c = *str++ & 037;
                        break;

                case '\\':
                        dp = "E\033^^\\\\::n\nr\rt\tb\bf\f";
                        c = *str++;
nextc:
                        if (*dp++ == c) {
                                c = *dp++;
                                break;
                        }
                        dp++;
                        if (*dp)
                                goto nextc;
                        if (isdigit(c)) {
                                c -= '0', i = 2;
                                do
                                        c <<= 3, c |= *str++ - '0';
                                while (--i && isdigit(*str));
                        }
                        break;
                }
                *cp++ = c;
        }
        *cp++ = 0;
        str = *area;
        *area = cp;
        return (str);
}