Commons IO
  1. Commons IO
  2. IO-90

Infinite loop in FileSystemUtils.freeSpaceWindows if share directory empty

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 1.2
    • Fix Version/s: 1.3
    • Component/s: Utilities
    • Labels:
      None
    • Environment:

      Windows NT or higher

      Description

      When using FileSystemUtils.freeSpaceWindows in an empty share directory, the line containing the free space does not exist which causes an infinite loop (the outerloop doesn't decrease the i index).

      In fact to deal with all possible errors, I propose to test the exitCode of the dir command.

      Here is a proposed new code for this function :

      /**

      • Find free space on the Windows platform using the 'dir' command.
        *
      • @param path the path to get free space for, including the colon
      • @return the amount of free drive space on the drive
      • @throws IOException if an error occurs
        */
        long freeSpaceWindows(String path) throws IOException {
        path = FilenameUtils.normalize(path);
        if (path.length() > 2 && path.charAt(1) == ':') { path = path.substring(0, 2); // seems to make it work }

      // build and run the 'dir' command
      String[] cmdAttrbs = new String[]

      {"cmd.exe", "/C", "dir /-c " + path}

      ;

      // read in the output of the command to an ArrayList
      BufferedReader in = null;
      String line = null;
      ArrayList lines = new ArrayList();
      int errorLevel = 0;

      try {
      Process proc = Runtime.getRuntime().exec(cmdAttrbs);
      in = new BufferedReader(
      new InputStreamReader(proc.getInputStream()));
      line = in.readLine();
      while (line != null)

      { line = line.toLowerCase().trim(); lines.add(line); line = in.readLine(); }

      proc.waitFor();
      errorLevel = proc.exitValue();

      } finally

      { IOUtils.closeQuietly(in); }

      if (lines.size() == 0)

      { // unknown problem, throw exception throw new IOException( "Command line 'dir /-c' did not return any info " + "for command '" + cmdAttrbs[2] + "'"); }

      if (errorLevel != 0) {
      if (errorLevel == 2)

      { // Empty directory : unable to calculate the freeSpace return Integer.MAX_VALUE; // ??? }

      else

      { // unknown problem, throw exception throw new IOException( "Command line 'dir /-c' error [" + errorLevel + "] for command '" + cmdAttrbs[2] + "'"); }

      }

      // now iterate over the lines we just read and find the LAST
      // non-empty line (the free space bytes should be in the last element
      // of the ArrayList anyway, but this will ensure it works even if it's
      // not, still assuming it is on the last non-blank line)
      long bytes = -1;
      int i = lines.size() - 1;
      int bytesStart = 0;
      int bytesEnd = 0;
      outerLoop: while (i > 0) {
      line = (String) lines.get;
      if (line.length() > 0) {
      // found it, so now read from the end of the line to find the
      // last numeric character on the line, then continue until we
      // find the first non-numeric character, and everything between
      // that and the last numeric character inclusive is our free
      // space bytes count
      int j = line.length() - 1;
      innerLoop1: while (j >= 0) {
      char c = line.charAt(j);
      if (Character.isDigit(c))

      { // found the last numeric character, this is the end of // the free space bytes count bytesEnd = j + 1; break innerLoop1; }

      j--;
      }
      innerLoop2: while (j >= 0) {
      char c = line.charAt(j);
      if (!Character.isDigit(c) && c != ',' && c != '.')

      { // found the next non-numeric character, this is the // beginning of the free space bytes count bytesStart = j + 1; break innerLoop2; }

      j--;
      }
      break outerLoop;
      } else

      { // If the last line is empty we are unable to parse the freeSpace throw new IOException( "Command line 'dir /-c' did not return valid info " + "for command '" + cmdAttrbs[2] + "'"); }

      }

      // remove commas and dots in the bytes count
      StringBuffer buf = new StringBuffer(line.substring(bytesStart, bytesEnd));
      for (int k = 0; k < buf.length(); k++) {
      if (buf.charAt(k) == ',' || buf.charAt(k) == '.')

      { buf.deleteCharAt(k--); }

      }
      bytes = Long.parseLong(buf.toString());
      return bytes;
      }

        Activity

          People

          • Assignee:
            Unassigned
            Reporter:
            Thomas Ledoux
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            Dates

            • Created:
              Updated:
              Resolved:

              Development