ndk-busybox/shell/glob.c

/*
 * Modified for the Android NDK by Gabor Cselle, http://www.gaborcselle.com/
 * Tested with Android NDK version 5b: http://developer.android.com/sdk/ndk/index.html
 * Last modified: March 3 2011
 *
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * 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.
 * 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)glob.c	8.3 (Berkeley) 10/13/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>


/*
 * glob(3) -- a superset of the one defined in POSIX 1003.2.
 *
 * The [!...] convention to negate a range is supported (SysV, Posix, ksh).
 *
 * Optional extra services, controlled by flags not defined by POSIX:
 *
 * GLOB_QUOTE:
 *	Escaping convention: \ inhibits any special meaning the following
 *	character might have (except \ at end of string is retained).
 * GLOB_MAGCHAR:
 *	Set in gl_flags if pattern contained a globbing character.
 * GLOB_NOMAGIC:
 *	Same as GLOB_NOCHECK, but it will only append pattern if it did
 *	not contain any magic characters.  [Used in csh style globbing]
 * GLOB_ALTDIRFUNC:
 *	Use alternately specified directory access functions.
 * GLOB_TILDE:
 *	expand ~user/foo to the /home/dir/of/user/foo
 * GLOB_BRACE:
 *	expand {1,2}{a,b} to 1a 1b 2a 2b
 * gl_matchc:
 *	Number of matches in the current invocation of glob.
 */

/*
 * Some notes on multibyte character support:
 * 1. Patterns with illegal byte sequences match nothing - even if
 *    GLOB_NOCHECK is specified.
 * 2. Illegal byte sequences in filenames are handled by treating them as
 *    single-byte characters with a value of the first byte of the sequence
 *    cast to wchar_t.
 * 3. State-dependent encodings are not currently supported.
 */

#include <sys/param.h>
#include <sys/stat.h>

#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include "glob.h"
#include <limits.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

//#include "collate.h" - NOTE(gabor): I took this out because it's not available for Android
//      and collate is only used once for string comparisons. As a side-effect, you might not
//      be able to match non-ASCII filenames.

#define	DOLLAR		'$'
#define	DOT		'.'
#define	EOS		'\0'
#define	LBRACKET	'['
#define	NOT		'!'
#define	QUESTION	'?'
#define	QUOTE		'\\'
#define	RANGE		'-'
#define	RBRACKET	']'
#define	SEP		'/'
#define	STAR		'*'
#define	TILDE		'~'
#define	UNDERSCORE	'_'
#define	LBRACE		'{'
#define	RBRACE		'}'
#define	SLASH		'/'
#define	COMMA		','

#define	M_PROTECT	0x40
#define	M_MASK		0xff


#define	M_ALL		'*'
#define	M_END		']'
#define	M_NOT		'!'
#define	M_ONE		'?'
#define	M_RNG		'-'
#define	M_SET		'['


static int g_stat(char *, struct stat *, glob_t *);
static int g_lstat(char *, struct stat *, glob_t *);
static DIR	*g_opendir(char *, glob_t *);
static int	 compare(const void *, const void *);
static int	 glob0(const char *, glob_t *, size_t *);
static int	 glob1(char *, glob_t *, size_t *);
static int	 glob2(char *, char *, char *, char *, glob_t *, size_t *);
static int	 glob3(char *, char *, char *, char *, char *, glob_t *, size_t *);
static int	 globextend(const char *, glob_t *, size_t *);
static const char *
		 globtilde(const char *, char *, size_t, glob_t *);
static int	 globexp1(const char *, glob_t *, size_t *);
static int	 globexp2(const char *, const char *, glob_t *, int *, size_t *);
static int	 match(char *, char *, char *);

int ismeta(char c) {
  return c == M_ALL || c == M_END || c == M_NOT || c == M_ONE || c == M_RNG || c == M_SET;
}

int
glob(const char *pattern, int flags, int (*errfunc)(const char *, int), glob_t *pglob)
{
	const char *patnext;
	size_t limit;
	char *bufnext, *bufend, patbuf[MAXPATHLEN], prot;

	patnext = pattern;
	if (!(flags & GLOB_APPEND)) {
		pglob->gl_pathc = 0;
		pglob->gl_pathv = NULL;
		if (!(flags & GLOB_DOOFFS))
			pglob->gl_offs = 0;
	}
	if (flags & GLOB_LIMIT) {
		limit = pglob->gl_matchc;
		if (limit == 0)
			limit = 131072;
	} else
		limit = 0;
	pglob->gl_flags = flags & ~GLOB_MAGCHAR;
	pglob->gl_errfunc = errfunc;
	pglob->gl_matchc = 0;

	bufnext = patbuf;
	bufend = bufnext + MAXPATHLEN - 1;
	if (flags & GLOB_NOESCAPE) {
          strncpy(bufnext, patnext, sizeof(patbuf));
	} else {
		/* Protect the quoted characters. */
		while (bufend >= bufnext && *patnext != EOS) {
			if (*patnext == QUOTE) {
				if (*++patnext == EOS) {
					*bufnext++ = QUOTE | M_PROTECT;
					continue;
				}
				prot = M_PROTECT;
			} else
				prot = 0;
			*bufnext++ = *patnext;
			patnext++;
		}
	}
	*bufnext = EOS;

	if (flags & GLOB_BRACE)
	    return globexp1(patbuf, pglob, &limit);
	else
	    return glob0(patbuf, pglob, &limit);
}

/*
 * Expand recursively a glob {} pattern. When there is no more expansion
 * invoke the standard globbing routine to glob the rest of the magic
 * characters
 */
static int
globexp1(const char *pattern, glob_t *pglob, size_t *limit)
{
	const char* ptr = pattern;
	int rv;

	/* Protect a single {}, for find(1), like csh */
	if (pattern[0] == LBRACE && pattern[1] == RBRACE && pattern[2] == EOS)
		return glob0(pattern, pglob, limit);

	while ((ptr = strchr(ptr, LBRACE)) != NULL)
		if (!globexp2(ptr, pattern, pglob, &rv, limit))
			return rv;

	return glob0(pattern, pglob, limit);
}


/*
 * Recursive brace globbing helper. Tries to expand a single brace.
 * If it succeeds then it invokes globexp1 with the new pattern.
 * If it fails then it tries to glob the rest of the pattern and returns.
 */
static int
globexp2(const char *ptr, const char *pattern, glob_t *pglob, int *rv, size_t *limit)
{
	int     i;
	char   *lm, *ls;
	const char *pe, *pm, *pm1, *pl;
	char    patbuf[MAXPATHLEN];

	/* copy part up to the brace */
	for (lm = patbuf, pm = pattern; pm != ptr; *lm++ = *pm++)
		continue;
	*lm = EOS;
	ls = lm;

	/* Find the balanced brace */
	for (i = 0, pe = ++ptr; *pe; pe++)
		if (*pe == LBRACKET) {
			/* Ignore everything between [] */
			for (pm = pe++; *pe != RBRACKET && *pe != EOS; pe++)
				continue;
			if (*pe == EOS) {
				/*
				 * We could not find a matching RBRACKET.
				 * Ignore and just look for RBRACE
				 */
				pe = pm;
			}
		}
		else if (*pe == LBRACE)
			i++;
		else if (*pe == RBRACE) {
			if (i == 0)
				break;
			i--;
		}

	/* Non matching braces; just glob the pattern */
	if (i != 0 || *pe == EOS) {
		*rv = glob0(patbuf, pglob, limit);
		return 0;
	}

	for (i = 0, pl = pm = ptr; pm <= pe; pm++)
		switch (*pm) {
		case LBRACKET:
			/* Ignore everything between [] */
			for (pm1 = pm++; *pm != RBRACKET && *pm != EOS; pm++)
				continue;
			if (*pm == EOS) {
				/*
				 * We could not find a matching RBRACKET.
				 * Ignore and just look for RBRACE
				 */
				pm = pm1;
			}
			break;

		case LBRACE:
			i++;
			break;

		case RBRACE:
			if (i) {
			    i--;
			    break;
			}
			/* FALLTHROUGH */
		case COMMA:
			if (i && *pm == COMMA)
				break;
			else {
				/* Append the current string */
				for (lm = ls; (pl < pm); *lm++ = *pl++)
					continue;
				/*
				 * Append the rest of the pattern after the
				 * closing brace
				 */
				for (pl = pe + 1; (*lm++ = *pl++) != EOS;)
					continue;

				/* Expand the current pattern */
				*rv = globexp1(patbuf, pglob, limit);

				/* move after the comma, to the next string */
				pl = pm + 1;
			}
			break;

		default:
			break;
		}
	*rv = 0;
	return 0;
}



/*
 * expand tilde from the passwd file.
 */
static const char *
globtilde(const char *pattern, char *patbuf, size_t patbuf_len, glob_t *pglob)
{
	struct passwd *pwd;
	char *h;
	const char *p;
	char *b, *eb;

	if (*pattern != TILDE || !(pglob->gl_flags & GLOB_TILDE))
		return pattern;

	/*
	 * Copy up to the end of the string or /
	 */
	eb = &patbuf[patbuf_len - 1];
	for (p = pattern + 1, h = (char *) patbuf;
	    h < (char *)eb && *p && *p != SLASH; *h++ = *p++)
		continue;

	*h = EOS;

	if (((char *) patbuf)[0] == EOS) {
		/*
		 * handle a plain ~ or ~/ by expanding $HOME first (iff
		 * we're not running setuid or setgid) and then trying
		 * the password file
		 */
#ifndef __GLIBC__
		if (issetugid() != 0 ||
		    (h = getenv("HOME")) == NULL) {
			if (((h = getlogin()) != NULL &&
			     (pwd = getpwnam(h)) != NULL) ||
			    (pwd = getpwuid(getuid())) != NULL)
				h = pwd->pw_dir;
			else
				return pattern;
		}
#endif
	}
	else {
		/*
		 * Expand a ~user
		 */
		if ((pwd = getpwnam((char*) patbuf)) == NULL)
			return pattern;
		else
			h = pwd->pw_dir;
	}

	/* Copy the home directory */
	for (b = patbuf; b < eb && *h; *b++ = *h++)
		continue;

	/* Append the rest of the pattern */
	while (b < eb && (*b++ = *p++) != EOS)
		continue;
	*b = EOS;

	return patbuf;
}


/*
 * The main glob() routine: compiles the pattern (optionally processing
 * quotes), calls glob1() to do the real pattern matching, and finally
 * sorts the list (unless unsorted operation is requested).  Returns 0
 * if things went well, nonzero if errors occurred.
 */
static int
glob0(const char *pattern, glob_t *pglob, size_t *limit)
{
	const char *qpatnext;
	int err;
	size_t oldpathc;
	char *bufnext, c, patbuf[MAXPATHLEN];

	qpatnext = globtilde(pattern, patbuf, MAXPATHLEN, pglob);
	oldpathc = pglob->gl_pathc;
	bufnext = patbuf;

	/* We don't need to check for buffer overflow any more. */
	while ((c = *qpatnext++) != EOS) {
		switch (c) {
		case LBRACKET:
			c = *qpatnext;
			if (c == NOT)
				++qpatnext;
			if (*qpatnext == EOS ||
			    strchr(qpatnext+1, RBRACKET) == NULL) {
				*bufnext++ = LBRACKET;
				if (c == NOT)
					--qpatnext;
				break;
			}
			*bufnext++ = M_SET;
			if (c == NOT)
				*bufnext++ = M_NOT;
			c = *qpatnext++;
			do {
				*bufnext++ = c;
				if (*qpatnext == RANGE &&
				    (c = qpatnext[1]) != RBRACKET) {
					*bufnext++ = M_RNG;
					*bufnext++ = c;
					qpatnext += 2;
				}
			} while ((c = *qpatnext++) != RBRACKET);
			pglob->gl_flags |= GLOB_MAGCHAR;
			*bufnext++ = M_END;
			break;
		case QUESTION:
			pglob->gl_flags |= GLOB_MAGCHAR;
			*bufnext++ = M_ONE;
			break;
		case STAR:
			pglob->gl_flags |= GLOB_MAGCHAR;
			/* collapse adjacent stars to one,
			 * to avoid exponential behavior
			 */
			if (bufnext == patbuf || bufnext[-1] != M_ALL)
			    *bufnext++ = M_ALL;
			break;
		default:
			*bufnext++ = c;
			break;
		}
	}
	*bufnext = EOS;

	if ((err = glob1(patbuf, pglob, limit)) != 0)
		return(err);

	/*
	 * If there was no match we are going to append the pattern
	 * if GLOB_NOCHECK was specified or if GLOB_NOMAGIC was specified
	 * and the pattern did not contain any magic characters
	 * GLOB_NOMAGIC is there just for compatibility with csh.
	 */
	if (pglob->gl_pathc == oldpathc) {
		if (((pglob->gl_flags & GLOB_NOCHECK) ||
		    ((pglob->gl_flags & GLOB_NOMAGIC) &&
			!(pglob->gl_flags & GLOB_MAGCHAR))))
			return(globextend(pattern, pglob, limit));
		else
			return(GLOB_NOMATCH);
	}
	if (!(pglob->gl_flags & GLOB_NOSORT))
		qsort(pglob->gl_pathv + pglob->gl_offs + oldpathc,
		    pglob->gl_pathc - oldpathc, sizeof(char *), compare);
	return(0);
}

static int
compare(const void *p, const void *q)
{
	return(strcmp(*(char **)p, *(char **)q));
}

static int
glob1(char *pattern, glob_t *pglob, size_t *limit)
{
	char pathbuf[MAXPATHLEN];

	/* A null pathname is invalid -- POSIX 1003.1 sect. 2.4. */
	if (*pattern == EOS)
		return(0);
	return(glob2(pathbuf, pathbuf, pathbuf + MAXPATHLEN - 1,
	    pattern, pglob, limit));
}

/*
 * The functions glob2 and glob3 are mutually recursive; there is one level
 * of recursion for each segment in the pattern that contains one or more
 * meta characters.
 */
static int
glob2(char *pathbuf, char *pathend, char *pathend_last, char *pattern,
      glob_t *pglob, size_t *limit)
{
	struct stat sb;
	char *p, *q;
	int anymeta;

	/*
	 * Loop over pattern segments until end of pattern or until
	 * segment with meta character found.
	 */
	for (anymeta = 0;;) {
		if (*pattern == EOS) {		/* End of pattern? */
			*pathend = EOS;
			if (g_lstat(pathbuf, &sb, pglob))
				return(0);

			if (((pglob->gl_flags & GLOB_MARK) &&
			    pathend[-1] != SEP) && (S_ISDIR(sb.st_mode)
			    || (S_ISLNK(sb.st_mode) &&
			    (g_stat(pathbuf, &sb, pglob) == 0) &&
			    S_ISDIR(sb.st_mode)))) {
				if (pathend + 1 > pathend_last)
					return (GLOB_ABORTED);
				*pathend++ = SEP;
				*pathend = EOS;
			}
			++pglob->gl_matchc;
			return(globextend(pathbuf, pglob, limit));
		}

		/* Find end of next segment, copy tentatively to pathend. */
		q = pathend;
		p = pattern;
		while (*p != EOS && *p != SEP) {
			if (ismeta(*p))
				anymeta = 1;
			if (q + 1 > pathend_last)
				return (GLOB_ABORTED);
			*q++ = *p++;
		}

		if (!anymeta) {		/* No expansion, do next segment. */
			pathend = q;
			pattern = p;
			while (*pattern == SEP) {
				if (pathend + 1 > pathend_last)
					return (GLOB_ABORTED);
				*pathend++ = *pattern++;
			}
		} else			/* Need expansion, recurse. */
			return(glob3(pathbuf, pathend, pathend_last, pattern, p,
			    pglob, limit));
	}
	/* NOTREACHED */
}

static int
glob3(char *pathbuf, char *pathend, char *pathend_last,
      char *pattern, char *restpattern,
      glob_t *pglob, size_t *limit)
{
	struct dirent *dp;
	DIR *dirp;
	int err;
	char buf[MAXPATHLEN];

	/*
	 * The readdirfunc declaration can't be prototyped, because it is
	 * assigned, below, to two functions which are prototyped in glob.h
	 * and dirent.h as taking pointers to differently typed opaque
	 * structures.
	 */
	struct dirent *(*readdirfunc)();

	if (pathend > pathend_last)
		return (GLOB_ABORTED);
	*pathend = EOS;
	errno = 0;

	if ((dirp = g_opendir(pathbuf, pglob)) == NULL) {
		/* TODO: don't call for ENOENT or ENOTDIR? */
		if (pglob->gl_errfunc) {
			if (pglob->gl_errfunc(buf, errno) ||
			    pglob->gl_flags & GLOB_ERR)
				return (GLOB_ABORTED);
		}
		return(0);
	}

	err = 0;

	/* Search directory for matching names. */
	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
		readdirfunc = pglob->gl_readdir;
	else
		readdirfunc = readdir;
	while ((dp = (*readdirfunc)(dirp))) {
		char *sc;
		char *dc;

		/* Initial DOT must be matched literally. */
		if (dp->d_name[0] == DOT && *pattern != DOT)
			continue;
		dc = pathend;
		sc = dp->d_name;
		while (dc < pathend_last) {
			if ((*dc++ = *sc) == EOS)
				break;
			sc++;
		}
		if (!match(pathend, pattern, restpattern)) {
			*pathend = EOS;
			continue;
		}
		err = glob2(pathbuf, --dc, pathend_last, restpattern,
		    pglob, limit);
		if (err)
			break;
	}

	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
		(*pglob->gl_closedir)(dirp);
	else
		closedir(dirp);
	return(err);
}


/*
 * Extend the gl_pathv member of a glob_t structure to accomodate a new item,
 * add the new item, and update gl_pathc.
 *
 * This assumes the BSD realloc, which only copies the block when its size
 * crosses a power-of-two boundary; for v7 realloc, this would cause quadratic
 * behavior.
 *
 * Return 0 if new item added, error code if memory couldn't be allocated.
 *
 * Invariant of the glob_t structure:
 *	Either gl_pathc is zero and gl_pathv is NULL; or gl_pathc > 0 and
 *	gl_pathv points to (gl_offs + gl_pathc + 1) items.
 */
static int
globextend(const char *path, glob_t *pglob, size_t *limit)
{
	char **pathv;
	size_t i, newsize, len;
	char *copy;
	const char *p;

	if (*limit && pglob->gl_pathc > *limit) {
		errno = 0;
		return (GLOB_NOSPACE);
	}

	newsize = sizeof(*pathv) * (2 + pglob->gl_pathc + pglob->gl_offs);
	pathv = pglob->gl_pathv ?
		    realloc((char *)pglob->gl_pathv, newsize) :
		    malloc(newsize);
	if (pathv == NULL) {
		if (pglob->gl_pathv) {
			free(pglob->gl_pathv);
			pglob->gl_pathv = NULL;
		}
		return(GLOB_NOSPACE);
	}

	if (pglob->gl_pathv == NULL && pglob->gl_offs > 0) {
		/* first time around -- clear initial gl_offs items */
		pathv += pglob->gl_offs;
		for (i = pglob->gl_offs + 1; --i > 0; )
			*--pathv = NULL;
	}
	pglob->gl_pathv = pathv;

	for (p = path; *p++;)
		continue;
	len = (size_t)(p - path);	/* XXX overallocation */
	if ((copy = malloc(len)) != NULL) {
          strncpy(copy, path, len);
          pathv[pglob->gl_offs + pglob->gl_pathc++] = copy;
	}
	pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
	return(copy == NULL ? GLOB_NOSPACE : 0);
}

/*
 * pattern matching function for filenames.  Each occurrence of the *
 * pattern causes a recursion level.
 */
static int
match(char *name, char *pat, char *patend)
{
	int ok, negate_range;
	char c, k;

	while (pat < patend) {
		c = *pat++;
		switch (c & M_MASK) {
		case M_ALL:
			if (pat == patend)
				return(1);
			do
			    if (match(name, pat, patend))
				    return(1);
			while (*name++ != EOS);
			return(0);
		case M_ONE:
			if (*name++ == EOS)
				return(0);
			break;
		case M_SET:
			ok = 0;
			if ((k = *name++) == EOS)
				return(0);
			if ((negate_range = ((*pat & M_MASK) == M_NOT)) != EOS)
				++pat;
			while (((c = *pat++) & M_MASK) != M_END)
				if ((*pat & M_MASK) == M_RNG) {
					// NOTE(gabor): This used to be as below, but I took out the collate.h
					// if (__collate_load_error ?
					//     CHAR(c) <= CHAR(k) && CHAR(k) <= CHAR(pat[1]) :
					//        __collate_range_cmp(CHAR(c), CHAR(k)) <= 0
					//     && __collate_range_cmp(CHAR(k), CHAR(pat[1])) <= 0
					//    )

					if (c <= k && k <= pat[1])
						ok = 1;
					pat += 2;
				} else if (c == k)
					ok = 1;
			if (ok == negate_range)
				return(0);
			break;
		default:
			if (*name++ != c)
				return(0);
			break;
		}
	}
	return(*name == EOS);
}

/* Free allocated data belonging to a glob_t structure. */
void
globfree(glob_t *pglob)
{
	size_t i;
	char **pp;

	if (pglob->gl_pathv != NULL) {
		pp = pglob->gl_pathv + pglob->gl_offs;
		for (i = pglob->gl_pathc; i--; ++pp)
			if (*pp)
				free(*pp);
		free(pglob->gl_pathv);
		pglob->gl_pathv = NULL;
	}
}

static int
g_stat(char *fn, struct stat *sb, glob_t *pglob)
{
	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
		return((*pglob->gl_stat)(fn, sb));
	return(stat(fn, sb));
}

static DIR *
g_opendir(char *str, glob_t *pglob)
{
	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
		return((*pglob->gl_opendir)(str));

	return(opendir(str));
}

static int
g_lstat(char *fn, struct stat *sb, glob_t *pglob)
{
	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
		return((*pglob->gl_lstat)(fn, sb));
	return(lstat(fn, sb));
}