path: root/StdLib/PosixLib/Glob/glob.c

/** @file
 * 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_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
 * GLOB_PERIOD:
 *  allow metacharacters to match leading dots in filenames.
 * GLOB_NO_DOTDIRS:
 *  . and .. are hidden from wildcards, even if GLOB_PERIOD is set.
 * gl_matchc:
 *  Number of matches in the current invocation of glob.
 *
 * 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.
 * 3. 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.

    glob.c  8.3 (Berkeley) 10/13/93
    NetBSD: glob.c,v 1.23.4.1 2010/07/19 18:14:08 riz Exp
 */
#pragma warning ( disable : 4244 )
#pragma warning ( disable : 4018 )

#include  <LibConfig.h>

#include <sys/cdefs.h>

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

#include <assert.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <glob.h>
//#include <pwd.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include "internal.h"

#ifdef HAVE_NBTOOL_CONFIG_H
#define NO_GETPW_R
#endif

#define GLOB_LIMIT_MALLOC     65536
#define GLOB_LIMIT_STAT         128
#define GLOB_LIMIT_READDIR    16384

#define GLOB_INDEX_MALLOC         0
#define GLOB_INDEX_STAT           1
#define GLOB_INDEX_READDIR        2

/*
 * XXX: For NetBSD 1.4.x compatibility. (kill me l8r)
 */
#ifndef _DIAGASSERT
#define _DIAGASSERT(a)
#endif

#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         ','

#ifndef USE_8BIT_CHARS

#define M_QUOTE       0x8000
#define M_PROTECT     0x4000
#define M_MASK        0xffff
#define M_ASCII       0x00ff

typedef u_short Char;

#else

#define M_QUOTE       (Char)0x80
#define M_PROTECT     (Char)0x40
#define M_MASK        (Char)0xff
#define M_ASCII       (Char)0x7f

typedef char Char;

#endif


#define CHAR(c)       ((Char)((c)&M_ASCII))
#define META(c)       ((Char)((c)|M_QUOTE))
#define M_ALL         META('*')
#define M_END         META(']')
#define M_NOT         META('!')
#define M_ONE         META('?')
#define M_RNG         META('-')
#define M_SET         META('[')
#define ismeta(c)     (((c)&M_QUOTE) != 0)

static int            compare(const void *, const void *);
static int            g_Ctoc(const Char *, char *, size_t);
static int            g_lstat(Char *, __gl_stat_t  *, glob_t *);
static DIR           *g_opendir(Char *, glob_t *);
static Char          *g_strchr(const Char *, int);
static int            g_stat(Char *, __gl_stat_t *, glob_t *);
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 *);
#ifdef DEBUG
static void           qprintf(const char *, Char *);
#endif

int
glob(
  const char *pattern,
  int flags,
  int (*errfunc)(const char *, int),
  glob_t *pglob
)
{
  const u_char *patnext;
  int c;
  Char *bufnext, *bufend, patbuf[MAXPATHLEN+1];
  /* 0 = malloc(), 1 = stat(), 2 = readdir() */
  size_t limit[] = { 0, 0, 0 };

  _DIAGASSERT(pattern != NULL);

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

  bufnext = patbuf;
  bufend = bufnext + MAXPATHLEN;
  if (flags & GLOB_NOESCAPE) {
    while (bufnext < bufend && (c = *patnext++) != EOS)
      *bufnext++ = c;
  } else {
    /* Protect the quoted characters. */
    while (bufnext < bufend && (c = *patnext++) != EOS)
      if (c == QUOTE) {
        if ((c = *patnext++) == EOS) {
          c = QUOTE;
          --patnext;
        }
        *bufnext++ = c | M_PROTECT;
      }
      else
        *bufnext++ = c;
  }
  *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;

  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(pglob != NULL);

  /* 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 = (const Char *) g_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, *pl;
  Char    patbuf[MAXPATHLEN + 1];

  _DIAGASSERT(ptr != NULL);
  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(pglob != NULL);
  _DIAGASSERT(rv != NULL);

  /* copy part up to the brace */
  for (lm = patbuf, pm = pattern; pm != ptr; *lm++ = *pm++)
    continue;
  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) {
    /*
     * we use `pattern', not `patbuf' here so that that
     * unbalanced braces are passed to the match
     */
    *rv = glob0(pattern, pglob, limit);
    return 0;
  }

  for (i = 0, pl = pm = ptr; pm <= pe; pm++) {
    switch (*pm) {
    case LBRACKET:
      /* Ignore everything between [] */
      for (pl = pm++; *pm != RBRACKET && *pm != EOS; pm++)
        continue;
      if (*pm == EOS) {
        /*
         * We could not find a matching RBRACKET.
         * Ignore and just look for RBRACE
         */
        pm = pl;
      }
      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 */
#ifdef DEBUG
        qprintf("globexp2:", patbuf);
#endif
        *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 patsize, glob_t *pglob)
{
  const char *h;
  const Char *p;
  Char *b;
  char *d;
  Char *pend = &patbuf[patsize / sizeof(Char)];

  pend--;

  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(patbuf != NULL);
  _DIAGASSERT(pglob != NULL);

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

  /* Copy up to the end of the string or / */
  for (p = pattern + 1, d = (char *)(void *)patbuf;
       d < (char *)(void *)pend && *p && *p != SLASH;
       *d++ = *p++)
    continue;

  if (d == (char *)(void *)pend)
    return NULL;

  *d = EOS;
  d = (char *)(void *)patbuf;

  if (*d == EOS) {
    /*
     * handle a plain ~ or ~/ by expanding $HOME
     * first and then trying the password file
     */
    if ((h = getenv("HOME")) == NULL) {
      return pattern;
    }
  }
  else {
    /*
     * Expand a ~user
     */
    return pattern;
  }

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

  if (b == pend)
    return NULL;

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

  if (b == pend)
    return NULL;

  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.  It is not an error
 * to find no matches.
 */
static int
glob0(const Char *pattern, glob_t *pglob, size_t *limit)
{
  const Char *qpatnext;
  int c, error;
  __gl_size_t oldpathc;
  Char *bufnext, patbuf[MAXPATHLEN+1];

  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(pglob != NULL);

  if ((qpatnext = globtilde(pattern, patbuf, sizeof(patbuf),
      pglob)) == NULL)
    return GLOB_ABEND;
  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 ||
          g_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++ = CHAR(c);
        if (*qpatnext == RANGE &&
            (c = qpatnext[1]) != RBRACKET) {
          *bufnext++ = M_RNG;
          *bufnext++ = CHAR(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++ = CHAR(c);
      break;
    }
  }
  *bufnext = EOS;
#ifdef DEBUG
  qprintf("glob0:", patbuf);
#endif

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

  if (pglob->gl_pathc == oldpathc) {
    /*
     * 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_flags & GLOB_NOCHECK) ||
        ((pglob->gl_flags & (GLOB_NOMAGIC|GLOB_MAGCHAR))
         == GLOB_NOMAGIC)) {
      return globextend(pattern, pglob, limit);
    } else {
      return GLOB_NOMATCH;
    }
  } else if (!(pglob->gl_flags & GLOB_NOSORT)) {
    qsort(pglob->gl_pathv + pglob->gl_offs + oldpathc,
        (size_t)pglob->gl_pathc - oldpathc, sizeof(char *),
        compare);
  }

  return 0;
}

static int
compare(const void *p, const void *q)
{

  _DIAGASSERT(p != NULL);
  _DIAGASSERT(q != NULL);

  return strcoll(*(const char * const *)p, *(const char * const *)q);
}

static int
glob1(Char *pattern, glob_t *pglob, size_t *limit)
{
  Char pathbuf[MAXPATHLEN+1];

  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(pglob != NULL);

  /* A null pathname is invalid -- POSIX 1003.1 sect. 2.4. */
  if (*pattern == EOS)
    return 0;
  /*
   * we save one character so that we can use ptr >= limit,
   * in the general case when we are appending non nul chars only.
   */
  return glob2(pathbuf, pathbuf,
      pathbuf + (sizeof(pathbuf) / sizeof(*pathbuf)) - 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 *pathlim, Char *pattern, glob_t *pglob,
    size_t *limit)
{
  __gl_stat_t sb;
  Char *p, *q;
  int anymeta;
  Char *pend;
  ptrdiff_t diff;

  _DIAGASSERT(pathbuf != NULL);
  _DIAGASSERT(pathend != NULL);
  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(pglob != NULL);

  /*
   * 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_LIMIT) &&
          limit[GLOB_INDEX_STAT]++ >= GLOB_LIMIT_STAT) {
        errno = 0;
        *pathend++ = SEP;
        *pathend = EOS;
        return GLOB_NOSPACE;
      }
      if (((pglob->gl_flags & GLOB_MARK) &&
          pathend[-1] != SEP) && (S_ISDIR(sb.st_mode) ||
//          (S_ISLNK(sb.st_mode) &&
          (0 &&
          (g_stat(pathbuf, &sb, pglob) == 0) &&
          S_ISDIR(sb.st_mode)))) {
        if (pathend >= pathlim)
          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 >= pathlim)
        return GLOB_ABORTED;
      *q++ = *p++;
    }

                /*
     * No expansion, or path ends in slash-dot shash-dot-dot,
     * do next segment.
     */
    if (pglob->gl_flags & GLOB_PERIOD) {
      for (pend = pathend; pend > pathbuf && pend[-1] == '/';
          pend--)
        continue;
      diff = pend - pathbuf;
    } else {
      /* XXX: GCC */
      diff = 0;
      pend = pathend;
    }

                if ((!anymeta) ||
        ((pglob->gl_flags & GLOB_PERIOD) &&
         (diff >= 1 && pend[-1] == DOT) &&
         (diff >= 2 && (pend[-2] == SLASH || pend[-2] == DOT)) &&
         (diff < 3 || pend[-3] == SLASH))) {
      pathend = q;
      pattern = p;
      while (*pattern == SEP) {
        if (pathend >= pathlim)
          return GLOB_ABORTED;
        *pathend++ = *pattern++;
      }
    } else      /* Need expansion, recurse. */
      return glob3(pathbuf, pathend, pathlim, pattern, p,
          pglob, limit);
  }
  /* NOTREACHED */
}

static int
glob3(Char *pathbuf, Char *pathend, Char *pathlim, Char *pattern,
    Char *restpattern, glob_t *pglob, size_t *limit)
{
  struct dirent *dp;
  DIR *dirp;
  int error;
  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)(void *);

  _DIAGASSERT(pathbuf != NULL);
  _DIAGASSERT(pathend != NULL);
  _DIAGASSERT(pattern != NULL);
  _DIAGASSERT(restpattern != NULL);
  _DIAGASSERT(pglob != NULL);

  *pathend = EOS;
  errno = 0;

  if ((dirp = g_opendir(pathbuf, pglob)) == NULL) {
    if (pglob->gl_errfunc) {
      if (g_Ctoc(pathbuf, buf, sizeof(buf)))
        return GLOB_ABORTED;
      if (pglob->gl_errfunc(buf, errno) ||
          pglob->gl_flags & GLOB_ERR)
        return GLOB_ABORTED;
    }
    /*
     * Posix/XOpen: glob should return when it encounters a
     * directory that it cannot open or read
     * XXX: Should we ignore ENOTDIR and ENOENT though?
     * I think that Posix had in mind EPERM...
     */
    if (pglob->gl_flags & GLOB_ERR)
      return GLOB_ABORTED;

    return 0;
  }

  error = 0;

  /* Search directory for matching names. */
  if (pglob->gl_flags & GLOB_ALTDIRFUNC)
    readdirfunc = pglob->gl_readdir;
  else
    readdirfunc = (struct dirent *(*)(void *)) readdir;
  while ((dp = (*readdirfunc)(dirp)) != NULL) {
    u_char *sc;
    Char *dc;

    if ((pglob->gl_flags & GLOB_LIMIT) &&
        limit[GLOB_INDEX_READDIR]++ >= GLOB_LIMIT_READDIR) {
      errno = 0;
      *pathend++ = SEP;
      *pathend = EOS;
      return GLOB_NOSPACE;
    }

    /*
     * Initial DOT must be matched literally, unless we have
     * GLOB_PERIOD set.
     */
    if ((pglob->gl_flags & GLOB_PERIOD) == 0)
      if (dp->FileName[0] == DOT && *pattern != DOT)
        continue;
    /*
     * If GLOB_NO_DOTDIRS is set, . and .. vanish.
     */
    if ((pglob->gl_flags & GLOB_NO_DOTDIRS) &&
        (dp->FileName[0] == DOT) &&
        ((dp->FileName[1] == EOS) ||
         ((dp->FileName[1] == DOT) && (dp->FileName[2] == EOS))))
      continue;
    /*
     * The resulting string contains EOS, so we can
     * use the pathlim character, if it is the nul
     */
    for (sc = (u_char *) dp->FileName, dc = pathend;
         dc <= pathlim && (*dc++ = *sc++) != EOS;)
      continue;

    /*
     * Have we filled the buffer without seeing EOS?
     */
    if (dc > pathlim && *pathlim != EOS) {
      /*
       * Abort when requested by caller, otherwise
       * reset pathend back to last SEP and continue
       * with next dir entry.
       */
      if (pglob->gl_flags & GLOB_ERR) {
        error = GLOB_ABORTED;
        break;
      }
      else {
        *pathend = EOS;
        continue;
      }
    }

    if (!match(pathend, pattern, restpattern)) {
      *pathend = EOS;
      continue;
    }
    error = glob2(pathbuf, --dc, pathlim, restpattern, pglob,
        limit);
    if (error)
      break;
  }

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

  /*
   * Again Posix X/Open issue with regards to error handling.
   */
  if ((error || errno) && (pglob->gl_flags & GLOB_ERR))
    return GLOB_ABORTED;

  return error;
}


/*
 * Extend the gl_pathv member of a glob_t structure to accommodate 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;

  _DIAGASSERT(path != NULL);
  _DIAGASSERT(pglob != NULL);

  newsize = sizeof(*pathv) * (2 + pglob->gl_pathc + pglob->gl_offs);
  pathv = pglob->gl_pathv ? realloc(pglob->gl_pathv, newsize) :
      malloc(newsize);
  if (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);
  limit[GLOB_INDEX_MALLOC] += len;
  if ((copy = malloc(len)) != NULL) {
    if (g_Ctoc(path, copy, len)) {
      free(copy);
      return GLOB_ABORTED;
    }
    pathv[pglob->gl_offs + pglob->gl_pathc++] = copy;
  }
  pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;

  if ((pglob->gl_flags & GLOB_LIMIT) &&
      (newsize + limit[GLOB_INDEX_MALLOC]) >= GLOB_LIMIT_MALLOC) {
    errno = 0;
    return GLOB_NOSPACE;
  }

  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;

  _DIAGASSERT(name != NULL);
  _DIAGASSERT(pat != NULL);
  _DIAGASSERT(patend != NULL);

  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) {
          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;

  _DIAGASSERT(pglob != NULL);

  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;
    pglob->gl_pathc = 0;
  }
}

static DIR *
g_opendir(Char *str, glob_t *pglob)
{
  char buf[MAXPATHLEN];

  _DIAGASSERT(str != NULL);
  _DIAGASSERT(pglob != NULL);

  if (!*str)
    (void)strlcpy(buf, ".", sizeof(buf));
  else {
    if (g_Ctoc(str, buf, sizeof(buf)))
      return NULL;
  }

  if (pglob->gl_flags & GLOB_ALTDIRFUNC)
    return (*pglob->gl_opendir)(buf);

  return opendir(buf);
}

static int
g_lstat(Char *fn, __gl_stat_t *sb, glob_t *pglob)
{
  char buf[MAXPATHLEN];

  _DIAGASSERT(fn != NULL);
  _DIAGASSERT(sb != NULL);
  _DIAGASSERT(pglob != NULL);

  if (g_Ctoc(fn, buf, sizeof(buf)))
    return -1;
  if (pglob->gl_flags & GLOB_ALTDIRFUNC)
    return (*pglob->gl_lstat)(buf, sb);
  return lstat(buf, sb);
}

static int
g_stat(Char *fn, __gl_stat_t *sb, glob_t *pglob)
{
  char buf[MAXPATHLEN];

  _DIAGASSERT(fn != NULL);
  _DIAGASSERT(sb != NULL);
  _DIAGASSERT(pglob != NULL);

  if (g_Ctoc(fn, buf, sizeof(buf)))
    return -1;
  if (pglob->gl_flags & GLOB_ALTDIRFUNC)
    return (*pglob->gl_stat)(buf, sb);
  return stat(buf, sb);
}

static Char *
g_strchr(const Char *str, int ch)
{

  _DIAGASSERT(str != NULL);

  do {
    if (*str == ch)
      return __UNCONST(str);
  } while (*str++);
  return NULL;
}

static int
g_Ctoc(const Char *str, char *buf, size_t len)
{
  char *dc;

  _DIAGASSERT(str != NULL);
  _DIAGASSERT(buf != NULL);

  if (len == 0)
    return 1;

  for (dc = buf; len && (*dc++ = *str++) != EOS; len--)
    continue;

  return len == 0;
}

#ifdef DEBUG
static void
qprintf(const char *str, Char *s)
{
  Char *p;

  _DIAGASSERT(str != NULL);
  _DIAGASSERT(s != NULL);

  (void)printf("%s:\n", str);
  for (p = s; *p; p++)
    (void)printf("%c", CHAR(*p));
  (void)printf("\n");
  for (p = s; *p; p++)
    (void)printf("%c", *p & M_PROTECT ? '"' : ' ');
  (void)printf("\n");
  for (p = s; *p; p++)
    (void)printf("%c", ismeta(*p) ? '_' : ' ');
  (void)printf("\n");
}
#endif