Compact: Compresses and Uncompresses NTFS Files and Folders

The Compact utility is the command line version of the compression functionality in My Computer or Windows NT Explorer. The Compact utility displays and alters the compression of folders and files on NTFS volumes. It also displays the compression state of folders. For more information about this utility, type compact /? at the command prompt. The table following describes the options.

The format of the command is:

compact [/c] [/u] [/s[:folder]] [/a] [/i] [/f] [/q] [filename [...]]

Option	Description

none	Displays the compression state of the current folder.
/c	Compresses the specified folder or file.
/u	Uncompresses the specified folder or file.
/s[:folder]	Specifies that the requested action (compress or uncompress) be applied to all subfolders of the specified folder, or to the current folder if none is specified.
/i	Ignores errors.
/f	Forces compression or uncompression of the specified folder or file.
/a	Displays files with the hidden or system attribute.
/q	Reports only the most essential information.
filename	Specifies a pattern, file, or folder. You can use multiple filenames and wild cards.

There are reasons why you would want to use this utility instead of My Computer or Windows NT Explorer:

You can use Compact in a batch script. Using the /i option enables you to skip files that cannot be opened when you are running in batch mode, such as when a file is already in use by another program.

If the system crashed when compression or uncompression was occurring, the file or folder is marked as Compressed or Uncompressed, even if the operation did not complete. You can force the operation to complete by using the Compact utility with the /f option (with either the /c or /u).

Note

The Compact utility automatically compresses or uncompresses all of the files and subfolders when you change the compression state of a folder. It does not ask whether you want to change the compression state of the files or subfolders in it.