LinuxCommandLibrary

ncdu

NCurses Disk Usage

TLDR

Analyze the current working directory

$ ncdu
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Colorize output
$ ncdu --color [dark|off]
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Analyze a given directory
$ ncdu [path/to/directory]
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Save results to a file
$ ncdu -o [path/to/file]
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Exclude files that match a pattern, argument can be given multiple times to add more patterns
$ ncdu --exclude '[*.txt]'
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Name

ncdu - NCurses Disk Usage

Synopsis

ncdu [-hqvx] [--exclude PATTERN] [-X FILE] dir

Description

ncdu (NCurses Disk Usage) is a curses-based version of the well-known 'du', and provides a fast way to see what directories are using your disk space.

Options

-h
Print a small help message
-q
Quiet mode. While calculating disk space, ncdu will update the screen 10 times a second by default, this will be decreased to once every 2 seconds in quiet mode. Use this feature to save bandwidth over remote connections.
-v
Print version.
-x
Only count files and directories on the same filesystem as the specified dir.
--exclude PATTERN
Exclude files that match PATTERN. This argument can be added multiple times to add more patterns.
-X FILE, --exclude-from FILE
Exclude files that match any pattern in FILE. Patterns should be separated by a newline.

Keys

?
Show help + keys + about screen
up, down j, k
Cycle through the items
right, enter, l
Open selected directory
left, <, h
Go to parent directory
n
Order by filename (press again for descending order)
s
Order by filesize (press again for descending order)
a
Toggle between showing disk usage and showing apparent size.
d
Delete the selected file or directory. An error message will be shown when the contents of the directory do not match or do not exist anymore on the filesystem.
t
Toggle dirs before files when sorting.
g
Toggle between showing percentage, graph, both, or none. Percentage is relative to the size of the current directory, graph is relative to the largest item in the current directory.
e
Show/hide 'hidden' or 'excluded' files and directories. Please note that even though you can't see the hidden files and directories, they are still there and they are still included in the directory sizes. If you suspect that the totals shown at the bottom of the screen are not correct, make sure you haven't enabled this option.
i
Show information about the current selected item.
r
Refresh/recalculate the current directory.
q
Quit

Hard Links

Every disk usage analysis utility has its own way of (not) counting hard links. There does not seem to be any universally agreed method of handling hard links, and it is even inconsistent among different versions of ncdu. This section explains what each version of ncdu does.

ncdu 1.5 and below does not support any hard link detection at all: each link is considered a separate inode and its size is counted for every link. This means that the displayed directory sizes are incorrect when analyzing directories which contain hard links.

ncdu 1.6 has basic hard link detection: When a link to a previously encountered inode is detected, the link is considered to have a file size of zero bytes. Its size is not counted again, and the link is indicated in the browser interface with a 'H' mark. The displayed directory sizes are only correct when all links to an inode reside within that directory. When this is not the case, the sizes may or may not be correct, depending on which links were considered as "duplicate" and which as "original". The indicated size of the topmost directory (that is, the one specified on the command line upon starting ncdu) is always correct.

ncdu 1.7 has improved hard link detection. Each file that has more than two links has the "H" mark visible in the browser interface. Each hard link is counted exactly once for every directory it appears in. The indicated size of each directory is therefore, correctly, the sum of the sizes of all unique inodes that can be found in that directory. Note, however, that this may not always be same as the space that will be reclaimed after deleting the directory, as some inodes may still be accessible from hard links outside it.

Bugs

Directory hard links are not supported. They will not be detected as being hard links, and will thus be scanned and counted multiple times.

Some minor glitches may appear when displaying filenames that contain multibyte or multicolumn characters.

Please report any other bugs you may find at the bug tracker, which can be found on the web site

at http://dev.yorhel.nl/ncdu

Author

Written by Yoran Heling <projects@yorhel.nl>.

See Also

du(1)

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