du: Estimate file space usagedu reports the space needed to represent a set of files.
Synopsis:
du [option]… [file]…
With no arguments, du reports the space needed to represent
the files at or under the current directory.
Normally the space is printed in units of
1024 bytes, but this can be overridden (see Block size).
Non-integer quantities are rounded up to the next higher unit.
If two or more hard links point to the same file, only one of the hard
links is counted. The file argument order affects which links
are counted, and changing the argument order may change the numbers
and entries that du outputs.
The program accepts the following options. Also see Common options.
Output a zero byte (ASCII NUL) at the end of each line, rather than a newline. This option enables other programs to parse the output even when that output would contain data with embedded newlines.
Show counts for all files, not just directories.
Print apparent sizes, rather than file system usage. The apparent size of a
file is the number of bytes reported by wc -c on regular files,
or more generally, ls -l --block-size=1 or stat --format=%s.
For example, a file containing the word ‘zoo’ with no newline would,
of course, have an apparent size of 3. Such a small file may require
anywhere from 0 to 16 KiB or more of file system space, depending on
the type and configuration of the file system on which the file resides.
However, a sparse file created with this command:
dd bs=1 seek=2GiB if=/dev/null of=big
has an apparent size of 2 GiB, yet on most modern file systems, it actually uses almost no space.
Apparent sizes are meaningful only for regular files and symbolic links. Other file types do not contribute to apparent size.
Scale sizes by size before printing them (see Block size). For example, -BG prints sizes in units of 1,073,741,824 bytes.
Equivalent to --apparent-size --block-size=1.
Print a grand total of all arguments after all arguments have been processed. This can be used to find out the total file system usage of a given set of files or directories.
Dereference symbolic links that are command line arguments. Does not affect other symbolic links. This is helpful for finding out the file system usage of directories, such as /usr/tmp, which are often symbolic links.
Show the total for each directory (and file if --all) that is at
most MAX_DEPTH levels down from the root of the hierarchy. The root
is at level 0, so du --max-depth=0 is equivalent to du -s.
Disallow processing files named on the command line, and instead process
those named in file file; each name being terminated by a zero byte
(ASCII NUL).
This is useful
when the list of file names is so long that it may exceed a command line
length limitation.
In such cases, running du via xargs is undesirable
because it splits the list into pieces and makes du print
with the --total (-c) option for each sublist rather than for the entire list.
One way to produce a list of ASCII NUL terminated file
names is with GNU
find, using its -print0 predicate.
If file is ‘-’ then the ASCII NUL terminated
file names are read from standard input.
Equivalent to --dereference-args (-D).
Append a size letter to each size, such as ‘M’ for mebibytes. Powers of 1024 are used, not 1000; ‘M’ stands for 1,048,576 bytes. This option is equivalent to --block-size=human-readable. Use the --si option if you prefer powers of 1000.
List inode usage information instead of block usage.
This option is useful for finding directories which contain many files, and
therefore eat up most of the inodes space of a file system (see df,
option --inodes).
It can well be combined with the options -a, -c,
-h, -l, -s, -S, -t and
-x; however, passing other options regarding the block size, for
example -b, -m and --apparent-size, is ignored.
Print sizes in 1024-byte blocks, overriding the default block size (see Block size). This option is equivalent to --block-size=1K.
Dereference symbolic links (show the file system space used by the file or directory that the link points to instead of the space used by the link).
Count the size of all files, even if they have appeared already (as a hard link).
Print sizes in 1,048,576-byte blocks, overriding the default block size (see Block size). This option is equivalent to --block-size=1M.
For each symbolic link encountered by du,
consider the file system space used by the symbolic link itself.
Normally, in the output of du (when not using --summarize),
the size listed next to a directory name, d, represents the sum
of sizes of all entries beneath d as well as the size of d itself.
With --separate-dirs, the size reported for a directory name,
d, will exclude the size of any subdirectories.
Append an SI-style abbreviation to each size, such as ‘M’ for megabytes. Powers of 1000 are used, not 1024; ‘M’ stands for 1,000,000 bytes. This option is equivalent to --block-size=si. Use the -h or --human-readable option if you prefer powers of 1024.
Display only a total for each argument.
Exclude entries based on a given size. The size refers to used blocks in normal mode (see Block size), or inodes count in conjunction with the --inodes option.
If size is positive, then du will only print entries with a size
greater than or equal to that.
If size is negative, then du will only print entries with a size
smaller than or equal to that.
Although GNU find can be used to find files of a certain size,
du’s --threshold option can be used to also filter
directories based on a given size.
When combined with the --apparent-size option, the --threshold option elides entries based on apparent size. When combined with the --inodes option, it elides entries based on inode counts.
Here’s how you would use --threshold to find directories with a size greater than or equal to 200 megabytes:
du --threshold=200MB
Here’s how you would use --threshold to find directories and files – the -a – with an apparent size smaller than or equal to 500 bytes:
du -a -t -500 --apparent-size
Here’s how you would use --threshold to find directories on the root file system with more than 20000 inodes used in the directory tree below:
du --inodes -x --threshold=20000 /
Show the most recent modification timestamp (mtime) of any file in the directory, or any of its subdirectories. See File timestamps.
Show the most recent status change timestamp (ctime) of any file in the directory, or any of its subdirectories. See File timestamps.
Show the most recent access timestamp (atime) of any file in the directory, or any of its subdirectories. See File timestamps.
List timestamps in style style. This option has an effect only if the --time option is also specified. The style should be one of the following:
List timestamps using format, where format is interpreted
like the format argument of date (see date: Print or set system date and time).
For example, --time-style="+%Y-%m-%d %H:%M:%S" causes
du to list timestamps like ‘2020-07-21 23:45:56’. As
with date, format’s interpretation is affected by the
LC_TIME locale category.
List timestamps in full using ISO 8601-like date, time, and time zone components with nanosecond precision, e.g., ‘2020-07-21 23:45:56.477817180 -0400’. This style is equivalent to ‘+%Y-%m-%d %H:%M:%S.%N %z’.
List ISO 8601 date and time components with minute precision, e.g., ‘2020-07-21 23:45’. These timestamps are shorter than ‘full-iso’ timestamps, and are usually good enough for everyday work. This style is equivalent to ‘+%Y-%m-%d %H:%M’.
List ISO 8601 dates for timestamps, e.g., ‘2020-07-21’. This style is equivalent to ‘+%Y-%m-%d’.
You can specify the default value of the --time-style option
with the environment variable TIME_STYLE; if TIME_STYLE is not set
the default style is ‘long-iso’. For compatibility with ls,
if TIME_STYLE begins with ‘+’ and contains a newline,
the newline and any later characters are ignored; if TIME_STYLE
begins with ‘posix-’ the ‘posix-’ is ignored; and if
TIME_STYLE is ‘locale’ it is ignored.
Like --exclude, except take the patterns to exclude from file, one per line. If file is ‘-’, take the patterns from standard input.
When recursing, skip subdirectories or files matching pattern.
For example, du --exclude='*.o' excludes files whose names
end in ‘.o’.
Skip directories that are on different file systems from the one that the argument being processed is on.
Since du relies on information reported by the operating
system, its output might not reflect the space consumed in the
underlying devices. For example;
du to underestimate the device space actually used.
du typically counts the space that would
be consumed if all files’ non-holes were rewritten, not the space
currently consumed.
For these reasons du might better be thought of as an
estimate of the size of a tar or other conventional backup
for a set of files, rather than as a measure of space consumed in the
underlying devices.
An exit status of zero indicates success, and a nonzero value indicates failure.