cplfile.c

BCAST Implementation for NS2

/*.......................................................................
 * Return a description of the last path-completion error that occurred.
 *
 * Input:
 *  cf    CompleteFile *  The path-completion resource object.
 * Output:
 *  return  const char *  The description of the last error.
 */
const char *_cf_last_error(CompleteFile *cf)
{
  return cf ? cf->errmsg : "NULL CompleteFile argument";
}

/*.......................................................................
 * Lookup the home directory of the specified user, or the current user
 * if no name is specified, appending it to output pathname.
 *
 * Input:
 *  cf  CompleteFile *  The pathname completion resource object.
 *  user  const char *  The username to lookup, or "" to lookup the
 *                      current user.
 * Output:
 *  return        int    0 - OK.
 *                       1 - Error.
 */
static int cf_expand_home_dir(CompleteFile *cf, const char *user)
{
/*
 * Attempt to lookup the home directory.
 */
  const char *home_dir = _hd_lookup_home_dir(cf->home, user);
/*
 * Failed?
 */
  if(!home_dir) {
    strncpy(cf->errmsg, _hd_last_home_dir_error(cf->home), ERRLEN);
    cf->errmsg[ERRLEN] = '\0';
    return 1;
  };
/*
 * Append the home directory to the pathname string.
 */
  if(_pn_append_to_path(cf->path, home_dir, -1, 0) == NULL) {
    strcpy(cf->errmsg, "Insufficient memory for home directory expansion");
    return 1;
  };
  return 0;
}

/*.......................................................................
 * Lookup and report all completions of a given username prefix.
 *
 * Input:
 *  cf     CompleteFile *  The filename-completion resource object.
 *  cpl  WordCompletion *  The object in which to record the completions.
 *  prefix   const char *  The prefix of the usernames to lookup.
 *  line     const char *  The command-line in which the username appears.
 *  word_start      int    The index within line[] of the start of the
 *                         username that is being completed.
 *  word_end        int    The index within line[] of the character which
 *                         follows the incomplete username.
 *  escaped         int    True if the completions need to have special
 *                         characters escaped.
 * Output:
 *  return          int    0 - OK.
 *                         1 - Error.
 */
static int cf_complete_username(CompleteFile *cf, WordCompletion *cpl,
				const char *prefix, const char *line,
				int word_start, int word_end, int escaped)
{
/*
 * Set up a container of anonymous arguments to be sent to the
 * username-lookup iterator.
 */
  CfHomeArgs args;
  args.cf = cf;
  args.cpl = cpl;
  args.prefix = prefix;
  args.line = line;
  args.word_start = word_start;
  args.word_end = word_end;
  args.escaped = escaped;
/*
 * Iterate through the list of users, recording those which start
 * with the specified prefix.
 */
  if(_hd_scan_user_home_dirs(cf->home, &args, cf_homedir_callback)) {
    strncpy(cf->errmsg, _hd_last_home_dir_error(cf->home), ERRLEN);
    cf->errmsg[ERRLEN] = '\0';
    return 1;
  };
  return 0;
}

/*.......................................................................
 * The user/home-directory scanner callback function (see homedir.h)
 * used by cf_complete_username().
 */
static HOME_DIR_FN(cf_homedir_callback)
{
/*
 * Get the file-completion resources from the anonymous data argument.
 */
  CfHomeArgs *args = (CfHomeArgs *) data;
  WordCompletion *cpl = args->cpl;
  CompleteFile *cf = args->cf;
/*
 * Get the length of the username prefix.
 */
  int prefix_len = strlen(args->prefix);
/*
 * Get the length of the latest user name that is to be compared to
 * the prefix.
 */
  int name_len = strlen(usrnam);
/*
 * See if the latest username starts with the prefix that we are
 * searching for, and record its suffix in the array of matches if so.
 */
  if(name_len >= prefix_len && strncmp(args->prefix, usrnam, prefix_len)==0) {
/*
 * Copy the username into the pathname work buffer, adding backslash
 * escapes where needed.
 */
    if(cf_prepare_suffix(cf, usrnam+prefix_len, args->escaped)) {
      strncpy(errmsg, cf->errmsg, maxerr);
      errmsg[maxerr] = '\0';
      return 1;
    };
/*
 * Report the completion suffix that was copied above.
 */
    if(cpl_add_completion(cpl, args->line, args->word_start, args->word_end,
			  cf->buff->name, FS_DIR_SEP, FS_DIR_SEP)) {
      strncpy(errmsg, cpl_last_error(cpl), maxerr);
      errmsg[maxerr] = '\0';
      return 1;
    };
  };
  return 0;
}

/*.......................................................................
 * Report possible completions of the filename in cf->path->name[].
 *
 * Input:
 *  cf      CompleteFile *  The file-completion resource object.
 *  cpl   WordCompletion *  The object in which to record the completions.
 *  line      const char *  The input line, as received by the callback
 *                          function.
 *  word_start       int    The index within line[] of the start of the
 *                          last component of the filename that is being
 *                          completed.
 *  word_end         int    The index within line[] of the character which
 *                          follows the incomplete filename.
 *  escaped          int    If true, escape special characters in the
 *                          completion suffixes.
 *  check_fn  CplCheckFn *  If not zero, this argument specifies a
 *                          function to call to ask whether a given
 *                          file should be included in the list
 *                          of completions.
 *  check_data      void *  Anonymous data to be passed to check_fn().
 * Output:
 *  return           int    0 - OK.
 *                          1 - Error.
 */
static int cf_complete_entry(CompleteFile *cf, WordCompletion *cpl,
			     const char *line, int word_start, int word_end,
			     int escaped, CplCheckFn *check_fn,
			     void *check_data)
{
  const char *dirpath;   /* The name of the parent directory */
  int start;             /* The index of the start of the last filename */
                         /*  component in the transcribed filename. */
  const char *prefix;    /* The filename prefix to be completed */
  int prefix_len;        /* The length of the filename prefix */
  const char *file_name; /* The lastest filename being compared */
  int waserr = 0;        /* True after errors */
  int terminated=0;      /* True if the directory part had to be terminated */
/*
 * Get the pathname string and its current length.
 */
  char *pathname = cf->path->name;
  int pathlen = strlen(pathname);
/*
 * Locate the start of the final component of the pathname.
 */
  for(start=pathlen - 1; start >= 0 &&
      strncmp(pathname + start, FS_DIR_SEP, FS_DIR_SEP_LEN) != 0; start--)
    ;
/*
 * Is the parent directory the root directory?
 */
  if(start==0 ||
     (start < 0 && strncmp(pathname, FS_ROOT_DIR, FS_ROOT_DIR_LEN) == 0)) {
    dirpath = FS_ROOT_DIR;
    start += FS_ROOT_DIR_LEN;
/*
 * If we found a directory separator then the part which precedes the
 * last component is the name of the directory to be opened.
 */
  } else if(start > 0) {
/*
 * The _dr_open_dir() function requires the directory name to be '\0'
 * terminated, so temporarily do this by overwriting the first character
 * of the directory separator.
 */
    pathname[start] = '\0';
    dirpath = pathname;
    terminated = 1;
/*
 * We reached the start of the pathname before finding a directory
 * separator, so arrange to open the current working directory.
 */
  } else {
    start = 0;
    dirpath = FS_PWD;
  };
/*
 * Attempt to open the directory.
 */
  if(_dr_open_dir(cf->dr, dirpath, NULL)) {
    const char *fmt = "Can't open directory: %.*s";
    sprintf(cf->errmsg, fmt, ERRLEN - strlen(fmt), dirpath);
    return 1;
  };
/*
 * If removed above, restore the directory separator and skip over it
 * to the start of the filename.
 */
  if(terminated) {
    memcpy(pathname + start, FS_DIR_SEP, FS_DIR_SEP_LEN);
    start += FS_DIR_SEP_LEN;
  };
/*
 * Get the filename prefix and its length.
 */
  prefix = pathname + start;
  prefix_len = strlen(prefix);
/*
 * Traverse the directory, looking for files who's prefixes match the
 * last component of the pathname.
 */
  while((file_name = _dr_next_file(cf->dr)) != NULL && !waserr) {
    int name_len = strlen(file_name);
/*
 * Is the latest filename a possible completion of the filename prefix?
 */
    if(name_len >= prefix_len && strncmp(prefix, file_name, prefix_len)==0) {
/*
 * When listing all files in a directory, don't list files that start
 * with '.'. This is how hidden files are denoted in UNIX.
 */
      if(prefix_len > 0 || file_name[0] != '.') {
/*
 * Copy the completion suffix into the work pathname cf->buff->name,
 * adding backslash escapes if needed.
 */
	if(cf_prepare_suffix(cf, file_name + prefix_len, escaped)) {
	  waserr = 1;
	} else {
/*
 * We want directories to be displayed with directory suffixes,
 * and other fully completed filenames to be followed by spaces.
 * To check the type of the file, append the current suffix
 * to the path being completed, check the filetype, then restore
 * the path to its original form.
 */
	  const char *cont_suffix = "";  /* The suffix to add if fully */
                                         /*  completed. */
	  const char *type_suffix = "";  /* The suffix to add when listing */
	  if(_pn_append_to_path(cf->path, file_name + prefix_len,
				-1, escaped) == NULL) {
	    strcpy(cf->errmsg, "Insufficient memory to complete filename.");
	    return 1;
	  };
/*
 * Specify suffixes according to the file type.
 */
	  if(_pu_path_is_dir(cf->path->name)) {
	    cont_suffix = FS_DIR_SEP;
	    type_suffix = FS_DIR_SEP;
	  } else if(!check_fn || check_fn(check_data, cf->path->name)) {
	    cont_suffix = " ";
	  } else {
	    cf->path->name[pathlen] = '\0';
	    continue;
	  };
/*
 * Remove the temporarily added suffix.
 */
	  cf->path->name[pathlen] = '\0';
/*
 * Record the latest completion.
 */
	  if(cpl_add_completion(cpl, line, word_start, word_end, cf->buff->name,
				type_suffix, cont_suffix))
	    waserr = 1;
	};
      };
    };
  };
/*
 * Close the directory.
 */
  _dr_close_dir(cf->dr);
  return waserr;
}

/*.......................................................................
 * Read a username or environment variable name, stopping when a directory
 * separator is seen, when the end of the string is reached, or the
 * output buffer overflows.
 *
 * Input:
 *  cf   CompleteFile *  The file-completion resource object.
 *  type         char *  The capitalized name of the type of name being read.
 *  string       char *  The string who's prefix contains the name.
 *  slen          int    The number of characters in string[].
 *  nambuf       char *  The output name buffer.
 *  nammax        int    The longest string that will fit in nambuf[], excluding
 *                       the '\0' terminator.
 * Output:
 *  return       char *  A pointer to nambuf on success. On error NULL is
 *                       returned and a description of the error is recorded
 *                       in cf->errmsg[].
 */
static char *cf_read_name(CompleteFile *cf, const char *type,
			  const char *string, int slen,
			  char *nambuf, int nammax)
{
  int namlen;         /* The number of characters in nambuf[] */
  const char *sptr;   /* A pointer into string[] */
/*
 * Work out the max number of characters that should be copied.
 */
  int nmax = nammax < slen ? nammax : slen;
/*
 * Get the environment variable name that follows the dollar.
 */
  for(sptr=string,namlen=0;
      namlen < nmax && (slen-namlen < FS_DIR_SEP_LEN ||
			strncmp(sptr, FS_DIR_SEP, FS_DIR_SEP_LEN) != 0);
      namlen++) {
    nambuf[namlen] = *sptr++;
  };
/*
 * Did the name overflow the buffer?
 */
  if(namlen >= nammax) {
    const char *fmt = "%.*s name too long";
    sprintf(cf->errmsg, fmt, ERRLEN - strlen(fmt), type);
    return NULL;
  };
/*
 * Terminate the string.
 */
  nambuf[namlen] = '\0';
  return nambuf;
}

/*.......................................................................
 * Using the work buffer cf->buff, make a suitably escaped copy of a
 * given completion suffix, ready to be passed to cpl_add_completion().
 *
 * Input:
 *  cf   CompleteFile *  The file-completion resource object.
 *  suffix       char *  The suffix to be copied.
 *  add_escapes   int    If true, escape special characters.
 * Output:
 *  return        int    0 - OK.
 *                       1 - Error.
 */
static int cf_prepare_suffix(CompleteFile *cf, const char *suffix,
			     int add_escapes)
{
  const char *sptr; /* A pointer into suffix[] */
  int nbsl;         /* The number of backslashes to add to the suffix */
  int i;
/*
 * How long is the suffix?
 */
  int suffix_len = strlen(suffix);
/*
 * Clear the work buffer.
 */
  _pn_clear_path(cf->buff);
/*
 * Count the number of backslashes that will have to be added to
 * escape spaces, tabs, backslashes and wildcard characters.
 */
  nbsl = 0;
  if(add_escapes) {
    for(sptr = suffix; *sptr; sptr++) {
      switch(*sptr) {
      case ' ': case '\t': case '\\': case '*': case '?': case '[':
	nbsl++;
	break;
      };
    };
  };
/*
 * Arrange for the output path buffer to have sufficient room for the
 * both the suffix and any backslashes that have to be inserted.
 */
  if(_pn_resize_path(cf->buff, suffix_len + nbsl) == NULL) {
    strcpy(cf->errmsg, "Insufficient memory to complete filename");
    return 1;
  };
/*
 * If the suffix doesn't need any escapes, copy it directly into the
 * work buffer.
 */
  if(nbsl==0) {
    strcpy(cf->buff->name, suffix);
  } else {
/*
 * Make a copy with special characters escaped?
 */
    if(nbsl > 0) {
      const char *src = suffix;
      char *dst = cf->buff->name;
      for(i=0; i<suffix_len; i++) {
	switch(*src) {
	case ' ': case '\t': case '\\': case '*': case '?': case '[':
	  *dst++ = '\\';
	};
	*dst++ = *src++;
      };
      *dst = '\0';
    };
  };
  return 0;
}