expand.c

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/*
 * Sort the pathnames that matched.
 */
    qsort(ef->result.files, ef->result.nfile, sizeof(ef->result.files[0]),
	  ef_cmp_strings);
  };
/*
 * Return the result container.
 */
  return &ef->result;
}

/*.......................................................................
 * Attempt to recursively match the given pattern with the contents of
 * the current directory, descending sub-directories as needed.
 *
 * Input:
 *  ef      ExpandFile *  The pathname expansion resource object.
 *  dr       DirReader *  The directory reader object of the directory
 *                        to be searched.
 *  pattern const char *  The pattern to match with files in the current
 *                        directory.
 *  separate       int    When appending a filename from the specified
 *                        directory to ef->pathname, insert a directory
 *                        separator between the existing pathname and
 *                        the filename, unless separate is zero.
 * Output:
 *  return         int    0 - OK.
 *                        1 - Error.
 */
static int ef_match_relative_pathname(ExpandFile *ef, DirReader *dr,
				       const char *pattern, int separate)
{
  const char *nextp;  /* The pointer to the character that follows the part */
                      /*  of the pattern that is to be matched with files */
                      /*  in the current directory. */
  char *file;         /* The name of the file being matched */
  int pathlen;        /* The length of ef->pathname[] on entry to this */
                      /*  function */
/*
 * Record the current length of the pathname string recorded in
 * ef->pathname[].
 */
  pathlen = strlen(ef->path->name);
/*
 * Get a pointer to the character that follows the end of the part of
 * the pattern that should be matched to files within the current directory.
 * This will either point to a directory separator, or to the '\0' terminator
 * of the pattern string.
 */
  for(nextp=pattern; *nextp && strncmp(nextp, FS_DIR_SEP, FS_DIR_SEP_LEN) != 0;
      nextp++)
    ;
/*
 * Read each file from the directory, attempting to match it to the
 * current pattern.
 */
  while((file=_dr_next_file(dr)) != NULL) {
/*
 * Does the latest file match the pattern up to nextp?
 */
    if(ef_string_matches_pattern(file, pattern, file[0]=='.', nextp)) {
/*
 * Append the new directory entry to the current matching pathname.
 */
      if((separate && _pn_append_to_path(ef->path, FS_DIR_SEP, -1, 0)==NULL) ||
	 _pn_append_to_path(ef->path, file, -1, 0)==NULL) {
	strcpy(ef->errmsg, "Insufficient memory to record path");
	return 1;
      };
/*
 * If we have reached the end of the pattern, record the accumulated
 * pathname in the list of matching files.
 */
      if(*nextp == '\0') {
	if(ef_record_pathname(ef, ef->path->name, 0))
	  return 1;
/*
 * If the matching directory entry is a subdirectory, and the
 * next character of the pattern is a directory separator,
 * recursively call the current function to scan the sub-directory
 * for matches.
 */
      } else if(_pu_path_is_dir(ef->path->name) &&
		strncmp(nextp, FS_DIR_SEP, FS_DIR_SEP_LEN) == 0) {
/*
 * If the pattern finishes with the directory separator, then
 * record the pathame as matching.
 */
	if(nextp[FS_DIR_SEP_LEN] == '\0') {
	  if(ef_record_pathname(ef, ef->path->name, 0))
	    return 1;
/*
 * Match files within the directory.
 */
	} else {
	  DirNode *subdnode = ef_open_dir(ef, ef->path->name);
	  if(subdnode) {
	    if(ef_match_relative_pathname(ef, subdnode->dr,
					   nextp+FS_DIR_SEP_LEN, 1)) {
	      subdnode = ef_close_dir(ef, subdnode);
	      return 1;
	    };
	    subdnode = ef_close_dir(ef, subdnode);
	  };
	};
      };
/*
 * Remove the latest filename from the pathname string, so that
 * another matching file can be appended.
 */
      ef->path->name[pathlen] = '\0';
    };
  };
  return 0;
}

/*.......................................................................
 * Record a new matching filename.
 *
 * Input:
 *  ef        ExpandFile *  The filename-match resource object.
 *  pathname  const char *  The pathname to record.
 *  remove_escapes   int    If true, remove backslash escapes in the
 *                          recorded copy of the pathname.
 * Output:
 *  return           int     0 - OK.
 *                           1 - Error (ef->errmsg will contain a
 *                                      description of the error).
 */
static int ef_record_pathname(ExpandFile *ef, const char *pathname,
			      int remove_escapes)
{
  char *copy;          /* The recorded copy of pathname[] */
/*
 * Attempt to make a copy of the pathname in the cache.
 */
  copy = ef_cache_pathname(ef, pathname, remove_escapes);
  if(!copy)
    return 1;
/*
 * If there isn't room to record a pointer to the recorded pathname in the
 * array of files, attempt to extend the array.
 */
  if(ef->result.nfile + 1 > ef->files_dim) {
    int files_dim = ef->files_dim + MATCH_BLK_FACT;
    char **files = (char **) realloc(ef->result.files,
				     files_dim * sizeof(files[0]));
    if(!files) {
      sprintf(ef->errmsg,
	      "Insufficient memory to record all of the matching filenames");
      return 1;
    };
    ef->result.files = files;
    ef->files_dim = files_dim;
  };
/*
 * Record a pointer to the new match.
 */
  ef->result.files[ef->result.nfile++] = copy;
  return 0;
}

/*.......................................................................
 * Record a pathname in the cache.
 *
 * Input:
 *  ef       ExpandFile *  The filename-match resource object.
 *  pathname       char *  The pathname to record.
 *  remove_escapes  int    If true, remove backslash escapes in the
 *                         copy of the pathname.
 * Output:
 *  return         char *  The pointer to the copy of the pathname.
 *                         On error NULL is returned and a description
 *                         of the error is left in ef->errmsg[].
 */
static char *ef_cache_pathname(ExpandFile *ef, const char *pathname,
			       int remove_escapes)
{
  char *copy = _sg_store_string(ef->sg, pathname, remove_escapes);
  if(!copy)
    strcpy(ef->errmsg, "Insufficient memory to store pathname");
  return copy;
}

/*.......................................................................
 * Clear the results of the previous expansion operation, ready for the
 * next.
 *
 * Input:
 *  ef    ExpandFile *  The pathname expansion resource object.
 */
static void ef_clear_files(ExpandFile *ef)
{
  _clr_StringGroup(ef->sg);
  _pn_clear_path(ef->path);
  ef->result.exists = 0;
  ef->result.nfile = 0;
  ef->errmsg[0] = '\0';
  return;
}

/*.......................................................................
 * Get a new directory reader object from the cache.
 *
 * Input:
 *  ef        ExpandFile *  The pathname expansion resource object.
 *  pathname  const char *  The pathname of the directory.
 * Output:
 *  return       DirNode *  The cache entry of the new directory reader,
 *                          or NULL on error. On error, ef->errmsg will
 *                          contain a description of the error.
 */
static DirNode *ef_open_dir(ExpandFile *ef, const char *pathname)
{
  char *errmsg = NULL;  /* An error message from a called function */
  DirNode *node;        /* The cache node used */
/*
 * Get the directory reader cache.
 */
  DirCache *cache = &ef->cache;
/*
 * Extend the cache if there are no free cache nodes.
 */
  if(!cache->next) {
    node = (DirNode *) _new_FreeListNode(cache->mem);
    if(!node) {
      sprintf(ef->errmsg, "Insufficient memory to open a new directory");
      return NULL;
    };
/*
 * Initialize the cache node.
 */
    node->next = NULL;
    node->prev = NULL;
    node->dr = NULL;
/*
 * Allocate a directory reader object.
 */
    node->dr = _new_DirReader();
    if(!node->dr) {
      sprintf(ef->errmsg, "Insufficient memory to open a new directory");
      node = (DirNode *) _del_FreeListNode(cache->mem, node);
      return NULL;
    };
/*
 * Append the node to the cache list.
 */
    node->prev = cache->tail;
    if(cache->tail)
      cache->tail->next = node;
    else
      cache->head = node;
    cache->next = cache->tail = node;
  };
/*
 * Get the first unused node, but don't remove it from the list yet.
 */
  node = cache->next;
/*
 * Attempt to open the specified directory.
 */
  if(_dr_open_dir(node->dr, pathname, &errmsg)) {
    strncpy(ef->errmsg, errmsg, ERRLEN);
    ef->errmsg[ERRLEN] = '\0';
    return NULL;
  };
/*
 * Now that we have successfully opened the specified directory,
 * remove the cache node from the list, and relink the list around it.
 */
  cache->next = node->next;
  if(node->prev)
    node->prev->next = node->next;
  else
    cache->head = node->next;
  if(node->next)
    node->next->prev = node->prev;
  else
    cache->tail = node->prev;
  node->next = node->prev = NULL;
/*
 * Return the successfully initialized cache node to the caller.
 */
  return node;
}

/*.......................................................................
 * Return a directory reader object to the cache, after first closing
 * the directory that it was managing.
 *
 * Input:
 *  ef    ExpandFile *  The pathname expansion resource object.
 *  node     DirNode *  The cache entry of the directory reader, as returned
 *                      by ef_open_dir().
 * Output:
 *  return   DirNode *  The deleted DirNode (ie. allways NULL).
 */
static DirNode *ef_close_dir(ExpandFile *ef, DirNode *node)
{
/*
 * Get the directory reader cache.
 */
  DirCache *cache = &ef->cache;
/*
 * Close the directory.
 */
  _dr_close_dir(node->dr);
/*
 * Return the node to the tail of the cache list.
 */
  node->next = NULL;
  node->prev = cache->tail;
  if(cache->tail)
    cache->tail->next = node;
  else
    cache->head = cache->tail = node;
  if(!cache->next)
    cache->next = node;
  return NULL;
}

/*.......................................................................
 * Return non-zero if the specified file name matches a given glob
 * pattern.
 *
 * Input:
 *  file     const char *  The file-name component to be matched to the pattern.
 *  pattern  const char *  The start of the pattern to match against file[].
 *  xplicit         int    If non-zero, the first character must be matched
 *                         explicitly (ie. not with a wildcard).
 *  nextp    const char *  The pointer to the the character following the
 *                         end of the pattern in pattern[].
 * Output:
 *  return    int          0 - Doesn't match.
 *                         1 - The file-name string matches the pattern.
 */
static int ef_string_matches_pattern(const char *file, const char *pattern,
				      int xplicit, const char *nextp)
{
  const char *pptr = pattern; /* The pointer used to scan the pattern */
  const char *fptr = file;    /* The pointer used to scan the filename string */
/*
 * Match each character of the pattern in turn.
 */
  while(pptr < nextp) {
/*
 * Handle the next character of the pattern.
 */
    switch(*pptr) {
/*
 * A match zero-or-more characters wildcard operator.
 */
    case '*':
/*
 * Skip the '*' character in the pattern.
 */
      pptr++;
/*
 * If wildcards aren't allowed, the pattern doesn't match.
 */
      if(xplicit)
	return 0;
/*
 * If the pattern ends with a the '*' wildcard, then the
 * rest of the filename matches this.
 */
      if(pptr >= nextp)
	return 1;
/*
 * Using the wildcard to match successively longer sections of
 * the remaining characters of the filename, attempt to match
 * the tail of the filename against the tail of the pattern.
 */
      for( ; *fptr; fptr++) {
	if(ef_string_matches_pattern(fptr, pptr, 0, nextp))
	  return 1;
      };
      return 0; /* The pattern following the '*' didn't match */
      break;
/*
 * A match-one-character wildcard operator.
 */
    case '?':
/*
 * If there is a character to be matched, skip it and advance the
 * pattern pointer.
 */
      if(!xplicit && *fptr) {
        fptr++;
        pptr++;
/*
 * If we hit the end of the filename string, there is no character
 * matching the operator, so the string doesn't match.
 */
      } else {
        return 0;
      };
      break;
/*
 * A character range operator, with the character ranges enclosed
 * in matching square brackets.
 */
    case '[':
      if(xplicit || !ef_matches_range(*fptr++, ++pptr, &pptr))
        return 0;
      break;
/*
 * A backslash in the pattern prevents the following character as
 * being seen as a special character.
 */
    case '\\':
      pptr++;
      /* Note fallthrough to default */
/*
 * A normal character to be matched explicitly.
 */
    default:
      if(*fptr == *pptr) {
        fptr++;
        pptr++;
      } else {