read_termcap.c

ncurses-5.4

/****************************************************************************
 * Copyright (c) 1998-2002,2003 Free Software Foundation, Inc.              *
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 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
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 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
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 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
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 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <[e-mail]> 1992,1995               *
 *     and: Eric S. Raymond <[e-mail]>                         *
 ****************************************************************************/

/*
 * Termcap compatibility support
 *
 * If your OS integrator didn't install a terminfo database, you can call
 * _nc_read_termcap_entry() to support reading and translating capabilities
 * from the system termcap file.  This is a kludge; it will bulk up and slow
 * down every program that uses ncurses, and translated termcap entries cannot
 * use full terminfo capabilities.  Don't use it unless you absolutely have to;
 * instead, get your system people to run tic(1) from root on the terminfo
 * master included with ncurses to translate it into a terminfo database.
 *
 * If USE_GETCAP is enabled, we use what is effectively a copy of the 4.4BSD
 * getcap code to fetch entries.  There are disadvantages to this; mainly that
 * getcap(3) does its own resolution, meaning that entries read in in this way
 * can't reference the terminfo tree.  The only thing it buys is faster startup
 * time, getcap(3) is much faster than our tic parser.
 */

#include <curses.priv.h>

#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <tic.h>
#include <term_entry.h>

MODULE_ID("$Id: read_termcap.c,v 1.61 2003/11/08 20:22:45 tom Exp $")

#if !PURE_TERMINFO

#if defined(__EMX__) || defined(__DJGPP__)
#define is_pathname(s) ((((s) != 0) && ((s)[0] == '/')) \
		  || (((s)[0] != 0) && ((s)[1] == ':')))
#else
#define is_pathname(s) ((s) != 0 && (s)[0] == '/')
#endif

#define TC_SUCCESS     0
#define TC_UNRESOLVED -1
#define TC_NOT_FOUND  -2
#define TC_SYS_ERR    -3
#define TC_REF_LOOP   -4

static char *
get_termpath(void)
{
    char *result;

    if (!use_terminfo_vars() || (result = getenv("TERMPATH")) == 0)
	result = TERMPATH;
    T(("TERMPATH is %s", result));
    return result;
}

#if USE_GETCAP

#if HAVE_BSD_CGETENT
#define _nc_cgetcap   cgetcap
#define _nc_cgetent(buf, oline, db_array, name) cgetent(buf, db_array, name)
#define _nc_cgetmatch cgetmatch
#define _nc_cgetset   cgetset
#else
static int _nc_cgetmatch(char *, const char *);
static int _nc_getent(char **, unsigned *, int *, int, char **, int, const char
		      *, int, char *);
static int _nc_nfcmp(const char *, char *);

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Casey Leedom of Lawrence Livermore National Laboratory.
 *
 * 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 acknowledgment:
 *	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.
 */

/* static char sccsid[] = "@(#)getcap.c	8.3 (Berkeley) 3/25/94"; */

#define	BFRAG		1024
#define	BSIZE		1024
#define	MAX_RECURSION	32	/* maximum getent recursion */

static size_t topreclen;	/* toprec length */
static char *toprec;		/* Additional record specified by cgetset() */
static int gottoprec;		/* Flag indicating retrieval of toprecord */

/*
 * Cgetset() allows the addition of a user specified buffer to be added to the
 * database array, in effect "pushing" the buffer on top of the virtual
 * database.  0 is returned on success, -1 on failure.
 */
static int
_nc_cgetset(const char *ent)
{
    if (ent == 0) {
	FreeIfNeeded(toprec);
	toprec = 0;
	topreclen = 0;
	return (0);
    }
    topreclen = strlen(ent);
    if ((toprec = typeMalloc(char, topreclen + 1)) == 0) {
	errno = ENOMEM;
	return (-1);
    }
    gottoprec = 0;
    (void) strcpy(toprec, ent);
    return (0);
}

/*
 * Cgetcap searches the capability record buf for the capability cap with type
 * `type'.  A pointer to the value of cap is returned on success, 0 if the
 * requested capability couldn't be found.
 *
 * Specifying a type of ':' means that nothing should follow cap (:cap:).  In
 * this case a pointer to the terminating ':' or NUL will be returned if cap is
 * found.
 *
 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
 * return 0.
 */
static char *
_nc_cgetcap(char *buf, const char *cap, int type)
{
    register const char *cp;
    register char *bp;

    bp = buf;
    for (;;) {
	/*
	 * Skip past the current capability field - it's either the
	 * name field if this is the first time through the loop, or
	 * the remainder of a field whose name failed to match cap.
	 */
	for (;;) {
	    if (*bp == '\0')
		return (0);
	    else if (*bp++ == ':')
		break;
	}

	/*
	 * Try to match (cap, type) in buf.
	 */
	for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
	    continue;
	if (*cp != '\0')
	    continue;
	if (*bp == '@')
	    return (0);
	if (type == ':') {
	    if (*bp != '\0' && *bp != ':')
		continue;
	    return (bp);
	}
	if (*bp != type)
	    continue;
	bp++;
	return (*bp == '@' ? 0 : bp);
    }
    /* NOTREACHED */
}

/*
 * Cgetent extracts the capability record name from the NULL terminated file
 * array db_array and returns a pointer to a malloc'd copy of it in buf.  Buf
 * must be retained through all subsequent calls to cgetcap, cgetnum, cgetflag,
 * and cgetstr, but may then be freed.
 *
 * Returns:
 *
 * positive #    on success (i.e., the index in db_array)
 * TC_UNRESOLVED if we had too many recurrences to resolve
 * TC_NOT_FOUND  if the requested record couldn't be found
 * TC_SYS_ERR    if a system error was encountered (e.g.,couldn't open a file)
 * TC_REF_LOOP   if a potential reference loop is detected
 */
static int
_nc_cgetent(char **buf, int *oline, char **db_array, const char *name)
{
    unsigned dummy;

    return (_nc_getent(buf, &dummy, oline, 0, db_array, -1, name, 0, 0));
}

/*
 * Getent implements the functions of cgetent.  If fd is non-negative,
 * *db_array has already been opened and fd is the open file descriptor.  We
 * do this to save time and avoid using up file descriptors for tc=
 * recursions.
 *
 * Getent returns the same success/failure codes as cgetent.  On success, a
 * pointer to a malloc'd capability record with all tc= capabilities fully
 * expanded and its length (not including trailing ASCII NUL) are left in
 * *cap and *len.
 *
 * Basic algorithm:
 *	+ Allocate memory incrementally as needed in chunks of size BFRAG
 *	  for capability buffer.
 *	+ Recurse for each tc=name and interpolate result.  Stop when all
 *	  names interpolated, a name can't be found, or depth exceeds
 *	  MAX_RECURSION.
 */
#define DOALLOC(size) typeRealloc(char, size, record)
static int
_nc_getent(
	      char **cap,	/* termcap-content */
	      unsigned *len,	/* length, needed for recursion */
	      int *beginning,	/* line-number at match */
	      int in_array,	/* index in 'db_array[] */
	      char **db_array,	/* list of files to search */
	      int fd,
	      const char *name,
	      int depth,
	      char *nfield)
{
    register char *r_end, *rp;
    int myfd = FALSE;
    char *record = 0;
    int tc_not_resolved;
    int current;
    int lineno;

    /*
     * Return with ``loop detected'' error if we've recurred more than
     * MAX_RECURSION times.
     */
    if (depth > MAX_RECURSION)
	return (TC_REF_LOOP);

    /*
     * Check if we have a top record from cgetset().
     */
    if (depth == 0 && toprec != 0 && _nc_cgetmatch(toprec, name) == 0) {
	if ((record = DOALLOC(topreclen + BFRAG)) == 0) {
	    errno = ENOMEM;
	    return (TC_SYS_ERR);
	}
	(void) strcpy(record, toprec);
	rp = record + topreclen + 1;
	r_end = rp + BFRAG;
	current = in_array;
    } else {
	int foundit;

	/*
	 * Allocate first chunk of memory.
	 */
	if ((record = DOALLOC(BFRAG)) == 0) {
	    errno = ENOMEM;
	    return (TC_SYS_ERR);
	}
	rp = r_end = record + BFRAG;
	foundit = FALSE;

	/*
	 * Loop through database array until finding the record.
	 */
	for (current = in_array; db_array[current] != 0; current++) {
	    int eof = FALSE;

	    /*
	     * Open database if not already open.
	     */
	    if (fd >= 0) {
		(void) lseek(fd, (off_t) 0, SEEK_SET);
	    } else if ((_nc_access(db_array[current], R_OK) < 0)
		       || (fd = open(db_array[current], O_RDONLY, 0)) < 0) {
		/* No error on unfound file. */
		if (errno == ENOENT)
		    continue;
		free(record);
		return (TC_SYS_ERR);
	    } else {
		myfd = TRUE;
	    }
	    lineno = 0;

	    /*
	     * Find the requested capability record ...
	     */
	    {
		char buf[2048];
		register char *b_end = buf;
		register char *bp = buf;
		register int c;

		/*
		 * Loop invariants:
		 *      There is always room for one more character in record.
		 *      R_end always points just past end of record.
		 *      Rp always points just past last character in record.
		 *      B_end always points just past last character in buf.
		 *      Bp always points at next character in buf.
		 */

		for (;;) {
		    int first = lineno + 1;

		    /*
		     * Read in a line implementing (\, newline)
		     * line continuation.
		     */
		    rp = record;
		    for (;;) {
			if (bp >= b_end) {
			    int n;

			    n = read(fd, buf, sizeof(buf));
			    if (n <= 0) {
				if (myfd)
				    (void) close(fd);
				if (n < 0) {
				    free(record);
				    return (TC_SYS_ERR);
				}
				fd = -1;
				eof = TRUE;
				break;
			    }
			    b_end = buf + n;
			    bp = buf;
			}

			c = *bp++;
			if (c == '\n') {
			    lineno++;
			    if (rp == record || *(rp - 1) != '\\')
				break;