du command

du - estimate file space usage

The du command in Linux is a utility used to estimate disk usage of files and directories. It’s perfect for finding out how much space a folder or file takes up, helping you manage storage.

Usage: du [OPTION]... [FILE]...

• FILE: The file or directory to analyze (defaults to the current directory if omitted).
• OPTION: Flags to modify output or behavior.

Common Options

Option	Description
-h	Human-readable sizes (e.g., MB, GB)
-a	Include all files, not just directories
-s	Summarize total size only
--max-depth	Limit subdirectory depth
--exclude	Exclude files matching a pattern
-c	Show a grand total

Examples

• Basic Usage

  Run du on a directory to see its total size in kilobytes (KB).

  du /home/user/docs
  • Output (example):

    4096    /home/user/docs
  • Shows the size of docs (4096 KB = 4 MB).

  Current Directory:

  du
  • Lists sizes for all subdirectories and a total for ..

• Human-Readable Output

  Use -h to display sizes in a readable format (e.g., KB, MB, GB).

  du -h /home/user/docs
  • Output:

    4.0M    /home/user/docs

• Including Subdirectories

  By default, du shows sizes for subdirectories too. Use -a to include files.

  du -ah /home/user/docs
  • Output:

    1.5M    /home/user/docs/file1.txt
    2.0M    /home/user/docs/file2.pdf
    512K    /home/user/docs/subdir/file3.txt
    4.0M    /home/user/docs
  • -a: Shows all files and directories.

• Total Size Only

  Use -s to summarize the total size of a directory.

  du -sh /home/user/docs
  • Output:

    4.0M    /home/user/docs
  • -s: Summarize total size only.

• Depth Control

  Use --max-depth=N to limit how many subdirectory levels are shown.

  du -h --max-depth=1 /home/user
  • Output:

    4.0M    /home/user/docs
    2.0G    /home/user/videos
    2.1G    /home/user
  • Shows only one level deep.

• Excluding Files

  Use --exclude=PATTERN to skip certain files or directories.

  du -sh --exclude="*.txt" /home/user/docs
  • Excludes .txt files from the total.

• Sorting Output

  Pipe du with sort for ordered results.

  du -ah /home/user/docs | sort -hr
  • Output:

    4.0M    /home/user/docs
    2.0M    /home/user/docs/file2.pdf
    1.5M    /home/user/docs/file1.txt
    512K    /home/user/docs/subdir/file3.txt
  • -hr: Sorts by size (human-readable), descending.

To get help related to the du command use --help option

$ du --help
Usage: du [OPTION]... [FILE]...
  or:  du [OPTION]... --files0-from=F
Summarize disk usage of the set of FILEs, recursively for directories.

Mandatory arguments to long options are mandatory for short options too.
  -0, --null            end each output line with NUL, not newline
  -a, --all             write counts for all files, not just directories
      --apparent-size   print apparent sizes, rather than disk usage; although
                          the apparent size is usually smaller, it may be
                          larger due to holes in ('sparse') files, internal
                          fragmentation, indirect blocks, and the like
  -B, --block-size=SIZE  scale sizes by SIZE before printing them; e.g.,
                           '-BM' prints sizes in units of 1,048,576 bytes;
                           see SIZE format below
  -b, --bytes           equivalent to '--apparent-size --block-size=1'
  -c, --total           produce a grand total
  -D, --dereference-args  dereference only symlinks that are listed on the
                          command line
  -d, --max-depth=N     print the total for a directory (or file, with --all)
                          only if it is N or fewer levels below the command
                          line argument;  --max-depth=0 is the same as
                          --summarize
      --files0-from=F   summarize disk usage of the
                          NUL-terminated file names specified in file F;
                          if F is -, then read names from standard input
  -H                    equivalent to --dereference-args (-D)
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
      --inodes          list inode usage information instead of block usage
  -k                    like --block-size=1K
  -L, --dereference     dereference all symbolic links
  -l, --count-links     count sizes many times if hard linked
  -m                    like --block-size=1M
  -P, --no-dereference  don't follow any symbolic links (this is the default)
  -S, --separate-dirs   for directories do not include size of subdirectories
      --si              like -h, but use powers of 1000 not 1024
  -s, --summarize       display only a total for each argument
  -t, --threshold=SIZE  exclude entries smaller than SIZE if positive,
                          or entries greater than SIZE if negative
      --time            show time of the last modification of any file in the
                          directory, or any of its subdirectories
      --time=WORD       show time as WORD instead of modification time:
                          atime, access, use, ctime or status
      --time-style=STYLE  show times using STYLE, which can be:
                            full-iso, long-iso, iso, or +FORMAT;
                            FORMAT is interpreted like in 'date'
  -X, --exclude-from=FILE  exclude files that match any pattern in FILE
      --exclude=PATTERN    exclude files that match PATTERN
  -x, --one-file-system    skip directories on different file systems
      --help     display this help and exit
      --version  output version information and exit

Display values are in units of the first available SIZE from --block-size,
and the DU_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

The SIZE argument is an integer and optional unit (example: 10K is 10*1024).
Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.

For more details, check the manual with man du