findcmd.c

android-w.song.android.widget

  /* If PATH is in the temporary environment for this command, don't use the
     hash table to search for the full pathname. */
  path = find_variable_internal ("PATH", 1);
  temp_path = path && tempvar_p (path);
  if (temp_path == 0 && path)
    path = (SHELL_VAR *)NULL;

  /* Don't waste time trying to find hashed data for a pathname
     that is already completely specified or if we're using a command-
     specific value for PATH. */
  if (path == 0 && absolute_program (pathname) == 0)
    hashed_file = phash_search (pathname);

  /* If a command found in the hash table no longer exists, we need to
     look for it in $PATH.  Thank you Posix.2.  This forces us to stat
     every command found in the hash table. */

  if (hashed_file && (posixly_correct || check_hashed_filenames))
    {
      st = file_status (hashed_file);
      if ((st & (FS_EXISTS|FS_EXECABLE)) != (FS_EXISTS|FS_EXECABLE))
	{
	  phash_remove (pathname);
	  free (hashed_file);
	  hashed_file = (char *)NULL;
	}
    }

  if (hashed_file)
    command = hashed_file;
  else if (absolute_program (pathname))
    /* A command containing a slash is not looked up in PATH or saved in
       the hash table. */
    command = savestring (pathname);
  else
    {
      /* If $PATH is in the temporary environment, we've already retrieved
	 it, so don't bother trying again. */
      if (temp_path)
	{
	  command = find_user_command_in_path (pathname, value_cell (path),
					       FS_EXEC_PREFERRED|FS_NODIRS);
	}
      else
	command = find_user_command (pathname);
      if (command && hashing_enabled && temp_path == 0)
	phash_insert ((char *)pathname, command, dot_found_in_search, 1);	/* XXX fix const later */
    }
  return (command);
}

char *
user_command_matches (name, flags, state)
     const char *name;
     int flags, state;
{
  register int i;
  int  path_index, name_len;
  char *path_list, *path_element, *match;
  struct stat dotinfo;
  static char **match_list = NULL;
  static int match_list_size = 0;
  static int match_index = 0;

  if (state == 0)
    {
      /* Create the list of matches. */
      if (match_list == 0)
	{
	  match_list_size = 5;
	  match_list = strvec_create (match_list_size);
	}

      /* Clear out the old match list. */
      for (i = 0; i < match_list_size; i++)
	match_list[i] = 0;

      /* We haven't found any files yet. */
      match_index = 0;

      if (absolute_program (name))
	{
	  match_list[0] = find_absolute_program (name, flags);
	  match_list[1] = (char *)NULL;
	  path_list = (char *)NULL;
	}
      else
	{
	  name_len = strlen (name);
	  file_to_lose_on = (char *)NULL;
	  dot_found_in_search = 0;
      	  stat (".", &dotinfo);
	  path_list = get_string_value ("PATH");
      	  path_index = 0;
	}

      while (path_list && path_list[path_index])
	{
	  path_element = get_next_path_element (path_list, &path_index);

	  if (path_element == 0)
	    break;

	  match = find_in_path_element (name, path_element, flags, name_len, &dotinfo);

	  free (path_element);

	  if (match == 0)
	    continue;

	  if (match_index + 1 == match_list_size)
	    {
	      match_list_size += 10;
	      match_list = strvec_resize (match_list, (match_list_size + 1));
	    }

	  match_list[match_index++] = match;
	  match_list[match_index] = (char *)NULL;
	  FREE (file_to_lose_on);
	  file_to_lose_on = (char *)NULL;
	}

      /* We haven't returned any strings yet. */
      match_index = 0;
    }

  match = match_list[match_index];

  if (match)
    match_index++;

  return (match);
}

static char *
find_absolute_program (name, flags)
     const char *name;
     int flags;
{
  int st;

  st = file_status (name);

  /* If the file doesn't exist, quit now. */
  if ((st & FS_EXISTS) == 0)
    return ((char *)NULL);

  /* If we only care about whether the file exists or not, return
     this filename.  Otherwise, maybe we care about whether this
     file is executable.  If it is, and that is what we want, return it. */
  if ((flags & FS_EXISTS) || ((flags & FS_EXEC_ONLY) && (st & FS_EXECABLE)))
    return (savestring (name));

  return (NULL);
}

static char *
find_in_path_element (name, path, flags, name_len, dotinfop)
     const char *name;
     char *path;
     int flags, name_len;
     struct stat *dotinfop;
{
  int status;
  char *full_path, *xpath;

  xpath = (*path == '~') ? bash_tilde_expand (path, 0) : path;

  /* Remember the location of "." in the path, in all its forms
     (as long as they begin with a `.', e.g. `./.') */
  if (dot_found_in_search == 0 && *xpath == '.')
    dot_found_in_search = same_file (".", xpath, dotinfop, (struct stat *)NULL);

  full_path = sh_makepath (xpath, name, 0);

  status = file_status (full_path);

  if (xpath != path)
    free (xpath);

  if ((status & FS_EXISTS) == 0)
    {
      free (full_path);
      return ((char *)NULL);
    }

  /* The file exists.  If the caller simply wants the first file, here it is. */
  if (flags & FS_EXISTS)
    return (full_path);

  /* If we have a readable file, and the caller wants a readable file, this
     is it. */
  if ((flags & FS_READABLE) && (status & FS_READABLE))
    return (full_path);

  /* If the file is executable, then it satisfies the cases of
      EXEC_ONLY and EXEC_PREFERRED.  Return this file unconditionally. */
  if ((status & FS_EXECABLE) && (flags & (FS_EXEC_ONLY|FS_EXEC_PREFERRED)) &&
      (((flags & FS_NODIRS) == 0) || ((status & FS_DIRECTORY) == 0)))
    {
      FREE (file_to_lose_on);
      file_to_lose_on = (char *)NULL;
      return (full_path);
    }

  /* The file is not executable, but it does exist.  If we prefer
     an executable, then remember this one if it is the first one
     we have found. */
  if ((flags & FS_EXEC_PREFERRED) && file_to_lose_on == 0)
    file_to_lose_on = savestring (full_path);

  /* If we want only executable files, or we don't want directories and
     this file is a directory, or we want a readable file and this file
     isn't readable, fail. */
  if ((flags & (FS_EXEC_ONLY|FS_EXEC_PREFERRED)) ||
      ((flags & FS_NODIRS) && (status & FS_DIRECTORY)) ||
      ((flags & FS_READABLE) && (status & FS_READABLE) == 0))
    {
      free (full_path);
      return ((char *)NULL);
    }
  else
    return (full_path);
}

/* This does the dirty work for find_user_command_internal () and
   user_command_matches ().
   NAME is the name of the file to search for.
   PATH_LIST is a colon separated list of directories to search.
   FLAGS contains bit fields which control the files which are eligible.
   Some values are:
      FS_EXEC_ONLY:		The file must be an executable to be found.
      FS_EXEC_PREFERRED:	If we can't find an executable, then the
				the first file matching NAME will do.
      FS_EXISTS:		The first file found will do.
      FS_NODIRS:		Don't find any directories.
*/
static char *
find_user_command_in_path (name, path_list, flags)
     const char *name;
     char *path_list;
     int flags;
{
  char *full_path, *path;
  int path_index, name_len;
  struct stat dotinfo;

  /* We haven't started looking, so we certainly haven't seen
     a `.' as the directory path yet. */
  dot_found_in_search = 0;

  if (absolute_program (name))
    {
      full_path = find_absolute_program (name, flags);
      return (full_path);
    }

  if (path_list == 0 || *path_list == '\0')
    return (savestring (name));		/* XXX */

  file_to_lose_on = (char *)NULL;
  name_len = strlen (name);
  stat (".", &dotinfo);
  path_index = 0;

  while (path_list[path_index])
    {
      /* Allow the user to interrupt out of a lengthy path search. */
      QUIT;

      path = get_next_path_element (path_list, &path_index);
      if (path == 0)
	break;

      /* Side effects: sets dot_found_in_search, possibly sets
	 file_to_lose_on. */
      full_path = find_in_path_element (name, path, flags, name_len, &dotinfo);
      free (path);

      /* This should really be in find_in_path_element, but there isn't the
	 right combination of flags. */
      if (full_path && is_directory (full_path))
	{
	  free (full_path);
	  continue;
	}

      if (full_path)
	{
	  FREE (file_to_lose_on);
	  return (full_path);
	}
    }

  /* We didn't find exactly what the user was looking for.  Return
     the contents of FILE_TO_LOSE_ON which is NULL when the search
     required an executable, or non-NULL if a file was found and the
     search would accept a non-executable as a last resort.  If the
     caller specified FS_NODIRS, and file_to_lose_on is a directory,
     return NULL. */
  if (file_to_lose_on && (flags & FS_NODIRS) && is_directory (file_to_lose_on))
    {
      free (file_to_lose_on);
      file_to_lose_on = (char *)NULL;
    }

  return (file_to_lose_on);
}