java.lang.Object
- org.apache.commons.io.FileSystemUtils

```
public class FileSystemUtils
extends java.lang.Object
```
General File System utilities.
This class provides static utility methods for general file system functions not provided via the JDK File class.
The current functions provided are:
- Get the free space on a drive
Since:

1.1

Version:

$Id: FileSystemUtils.java 1304052 2012-03-22 20:55:29Z ggregory $

Field Summary

Fields
Modifier and Type	Field	Description
`private static java.lang.String`	`DF`	The path to df
`private static int`	`INIT_PROBLEM`	Operating system state flag for error.
`private static FileSystemUtils`	`INSTANCE`	Singleton instance, used mainly for testing.
`private static int`	`OS`	The operating system flag.
`private static int`	`OTHER`	Operating system state flag for neither Unix nor Windows.
`private static int`	`POSIX_UNIX`	Operating system state flag for Posix flavour Unix.
`private static int`	`UNIX`	Operating system state flag for Unix.
`private static int`	`WINDOWS`	Operating system state flag for Windows.

Constructor Summary

Constructors
Constructor Description

FileSystemUtils()
Instances should NOT be constructed in standard programming.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static long`	`freeSpace(java.lang.String path)`	Deprecated. Use freeSpaceKb(String) Deprecated from 1.3, may be removed in 2.0
`static long`	`freeSpaceKb()`	Returns the disk size of the volume which holds the working directory.
`static long`	`freeSpaceKb(long timeout)`	Returns the disk size of the volume which holds the working directory.
`static long`	`freeSpaceKb(java.lang.String path)`	Returns the free space on a drive or volume in kilobytes by invoking the command line.
`static long`	`freeSpaceKb(java.lang.String path, long timeout)`	Returns the free space on a drive or volume in kilobytes by invoking the command line.
`(package private) long`	`freeSpaceOS(java.lang.String path, int os, boolean kb, long timeout)`	Returns the free space on a drive or volume in a cross-platform manner.
`(package private) long`	`freeSpaceUnix(java.lang.String path, boolean kb, boolean posix, long timeout)`	Find free space on the *nix platform using the 'df' command.
`(package private) long`	`freeSpaceWindows(java.lang.String path, long timeout)`	Find free space on the Windows platform using the 'dir' command.
`(package private) java.lang.Process`	`openProcess(java.lang.String[] cmdAttribs)`	Opens the process to the operating system.
`(package private) long`	`parseBytes(java.lang.String freeSpace, java.lang.String path)`	Parses the bytes from a string.
`(package private) long`	`parseDir(java.lang.String line, java.lang.String path)`	Parses the Windows dir response last line
`(package private) java.util.List<java.lang.String>`	`performCommand(java.lang.String[] cmdAttribs, int max, long timeout)`	Performs the os command.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - INSTANCE
```
private static final FileSystemUtils INSTANCE
```
    Singleton instance, used mainly for testing.
  - INIT_PROBLEM
```
private static final int INIT_PROBLEM
```
    Operating system state flag for error.
    
    See Also:
    
    Constant Field Values
  - OTHER
```
private static final int OTHER
```
    Operating system state flag for neither Unix nor Windows.
    
    See Also:
    
    Constant Field Values
  - WINDOWS
```
private static final int WINDOWS
```
    Operating system state flag for Windows.
    
    See Also:
    
    Constant Field Values
  - UNIX
```
private static final int UNIX
```
    Operating system state flag for Unix.
    
    See Also:
    
    Constant Field Values
  - POSIX_UNIX
```
private static final int POSIX_UNIX
```
    Operating system state flag for Posix flavour Unix.
    
    See Also:
    
    Constant Field Values
  - OS
```
private static final int OS
```
    The operating system flag.
  - DF
```
private static final java.lang.String DF
```
    The path to df
- Constructor Detail
  - FileSystemUtils
```
public FileSystemUtils()
```
    Instances should NOT be constructed in standard programming.
- Method Detail
  - freeSpace
```
@Deprecated
public static long freeSpace(java.lang.String path)
                      throws java.io.IOException
```
    Deprecated.
    Use freeSpaceKb(String) Deprecated from 1.3, may be removed in 2.0
    Returns the free space on a drive or volume by invoking the command line. This method does not normalize the result, and typically returns bytes on Windows, 512 byte units on OS X and kilobytes on Unix. As this is not very useful, this method is deprecated in favour of freeSpaceKb(String) which returns a result in kilobytes.
    Note that some OS's are NOT currently supported, including OS/390, OpenVMS.
    FileSystemUtils.freeSpace("C:"); // Windows FileSystemUtils.freeSpace("/volume"); // *nix
    The free space is calculated via the command line. It uses 'dir /-c' on Windows and 'df' on *nix.
    Parameters:
    
    path - the path to get free space for, not null, not empty on Unix
    
    Returns:
    
    the amount of free drive space on the drive or volume
    
    Throws:
    
    java.lang.IllegalArgumentException - if the path is invalid
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
    
    Since:
    
    1.1, enhanced OS support in 1.2 and 1.3
  - freeSpaceKb
```
public static long freeSpaceKb(java.lang.String path)
                        throws java.io.IOException
```
    Returns the free space on a drive or volume in kilobytes by invoking the command line.
    FileSystemUtils.freeSpaceKb("C:"); // Windows FileSystemUtils.freeSpaceKb("/volume"); // *nix
    The free space is calculated via the command line. It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.
    In order to work, you must be running Windows, or have a implementation of Unix df that supports GNU format when passed -k (or -kP). If you are going to rely on this code, please check that it works on your OS by running some simple tests to compare the command line with the output from this class. If your operating system isn't supported, please raise a JIRA call detailing the exact result from df -k and as much other detail as possible, thanks.
    Parameters:
    
    path - the path to get free space for, not null, not empty on Unix
    
    Returns:
    
    the amount of free drive space on the drive or volume in kilobytes
    
    Throws:
    
    java.lang.IllegalArgumentException - if the path is invalid
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
    
    Since:
    
    1.2, enhanced OS support in 1.3
  - freeSpaceKb
```
public static long freeSpaceKb(java.lang.String path,
                               long timeout)
                        throws java.io.IOException
```
    Returns the free space on a drive or volume in kilobytes by invoking the command line.
    FileSystemUtils.freeSpaceKb("C:"); // Windows FileSystemUtils.freeSpaceKb("/volume"); // *nix
    The free space is calculated via the command line. It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.
    In order to work, you must be running Windows, or have a implementation of Unix df that supports GNU format when passed -k (or -kP). If you are going to rely on this code, please check that it works on your OS by running some simple tests to compare the command line with the output from this class. If your operating system isn't supported, please raise a JIRA call detailing the exact result from df -k and as much other detail as possible, thanks.
    Parameters:
    
    path - the path to get free space for, not null, not empty on Unix
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the amount of free drive space on the drive or volume in kilobytes
    
    Throws:
    
    java.lang.IllegalArgumentException - if the path is invalid
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
    
    Since:
    
    2.0
  - freeSpaceKb
```
public static long freeSpaceKb()
                        throws java.io.IOException
```
    Returns the disk size of the volume which holds the working directory.
    Identical to:
    freeSpaceKb(new File(".").getAbsolutePath())
    Returns:
    
    the amount of free drive space on the drive or volume in kilobytes
    
    Throws:
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
    
    Since:
    
    2.0
  - freeSpaceKb
```
public static long freeSpaceKb(long timeout)
                        throws java.io.IOException
```
    Returns the disk size of the volume which holds the working directory.
    Identical to:
    freeSpaceKb(new File(".").getAbsolutePath())
    Parameters:
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the amount of free drive space on the drive or volume in kilobytes
    
    Throws:
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
    
    Since:
    
    2.0
  - freeSpaceOS
```
long freeSpaceOS(java.lang.String path,
                 int os,
                 boolean kb,
                 long timeout)
          throws java.io.IOException
```
    Returns the free space on a drive or volume in a cross-platform manner. Note that some OS's are NOT currently supported, including OS/390.
    FileSystemUtils.freeSpace("C:"); // Windows FileSystemUtils.freeSpace("/volume"); // *nix
    The free space is calculated via the command line. It uses 'dir /-c' on Windows and 'df' on *nix.
    Parameters:
    
    path - the path to get free space for, not null, not empty on Unix
    
    os - the operating system code
    
    kb - whether to normalize to kilobytes
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the amount of free drive space on the drive or volume
    
    Throws:
    
    java.lang.IllegalArgumentException - if the path is invalid
    
    java.lang.IllegalStateException - if an error occurred in initialisation
    
    java.io.IOException - if an error occurs when finding the free space
  - freeSpaceWindows
```
long freeSpaceWindows(java.lang.String path,
                      long timeout)
               throws java.io.IOException
```
    Find free space on the Windows platform using the 'dir' command.
    
    Parameters:
    
    path - the path to get free space for, including the colon
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the amount of free drive space on the drive
    
    Throws:
    
    java.io.IOException - if an error occurs
  - parseDir
```
long parseDir(java.lang.String line,
              java.lang.String path)
       throws java.io.IOException
```
    Parses the Windows dir response last line
    
    Parameters:
    
    line - the line to parse
    
    path - the path that was sent
    
    Returns:
    
    the number of bytes
    
    Throws:
    
    java.io.IOException - if an error occurs
  - freeSpaceUnix
```
long freeSpaceUnix(java.lang.String path,
                   boolean kb,
                   boolean posix,
                   long timeout)
            throws java.io.IOException
```
    Find free space on the *nix platform using the 'df' command.
    
    Parameters:
    
    path - the path to get free space for
    
    kb - whether to normalize to kilobytes
    
    posix - whether to use the posix standard format flag
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the amount of free drive space on the volume
    
    Throws:
    
    java.io.IOException - if an error occurs
  - parseBytes
```
long parseBytes(java.lang.String freeSpace,
                java.lang.String path)
         throws java.io.IOException
```
    Parses the bytes from a string.
    
    Parameters:
    
    freeSpace - the free space string
    
    path - the path
    
    Returns:
    
    the number of bytes
    
    Throws:
    
    java.io.IOException - if an error occurs
  - performCommand
```
java.util.List<java.lang.String> performCommand(java.lang.String[] cmdAttribs,
                                                int max,
                                                long timeout)
                                         throws java.io.IOException
```
    Performs the os command.
    
    Parameters:
    
    cmdAttribs - the command line parameters
    
    max - The maximum limit for the lines returned
    
    timeout - The timout amount in milliseconds or no timeout if the value is zero or less
    
    Returns:
    
    the parsed data
    
    Throws:
    
    java.io.IOException - if an error occurs
  - openProcess
```
java.lang.Process openProcess(java.lang.String[] cmdAttribs)
                       throws java.io.IOException
```
    Opens the process to the operating system.
    
    Parameters:
    
    cmdAttribs - the command line parameters
    
    Returns:
    
    the process
    
    Throws:
    
    java.io.IOException - if an error occurs

Class FileSystemUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

INSTANCE

INIT_PROBLEM

OTHER

WINDOWS

UNIX

POSIX_UNIX

OS

DF

Constructor Detail

FileSystemUtils

Method Detail

freeSpace

freeSpaceKb

freeSpaceKb

freeSpaceKb

freeSpaceKb

freeSpaceOS

freeSpaceWindows

parseDir

freeSpaceUnix

parseBytes

performCommand

openProcess