|-A||Display the apparent size instead of the disk usage. This can be helpful when operating on compressed volumes or sparse files.|
|Calculate block counts in blocksize byte blocks. This is different from the -h, -k, -m and -g options or setting BLOCKSIZE and gives an estimate of how much space the examined file hierarchy would require on a filesystem with the given blocksize. Unless in -A mode, blocksize is rounded up to the next multiple of 512.|
|-H||Symbolic links on the command line are followed, symbolic links in file hierarchies are not followed.|
|Ignore files and directories matching the specified mask.|
|-L||Symbolic links on the command line and in file hierarchies are followed.|
|-P||No symbolic links are followed. This is the default.|
|-a||Display an entry for each file in a file hierarchy.|
|-c||Display a grand total.|
|Display an entry for all files and directories depth directories deep.|
|-g||Display block counts in 1073741824-byte (1 GiB) blocks.|
|-h||"Human-readable" output. Use unit suffixes: Byte, Kilobyte, Megabyte, Gigabyte, Terabyte and Petabyte.|
|-k||Display block counts in 1024-byte (1 kiB) blocks.|
|-l||If a file has multiple hard links, count its size multiple times. The default behavior of du is to count files with multiple hard links only once. When the -l option is specified, the hard link checks are disabled, and these files are counted (and displayed) as many times as they are found.|
|-m||Display block counts in 1048576-byte (1 MiB) blocks.|
|-n||Ignore files and directories with user "nodump" flag (UF_NODUMP) set.|
|-r||Generate messages about directories that cannot be read, files that cannot be opened, and so on. This is the default case. This option exists solely for conformance with -xpg4.|
|-s||Display an entry for each specified file. (Equivalent to -d 0)|
|Display only entries for which size exceeds threshold. If threshold is negative, display only entries for which size is less than the absolute value of threshold.|
|-x||File system mount points are not traversed.|
The du utility counts the storage used by symbolic links and not the files they reference unless the -H or -L option is specified. If either the -H or -L option is specified, storage used by any symbolic links which are followed is not counted (or displayed). The -H , -L and -P options override each other and the commands actions are determined by the last one specified.
The -h, -k and -m options all override each other; the last one specified determines the block counts used.
BLOCKSIZE If the environment variable BLOCKSIZE is set, and the -h, -k or -m options are not specified, the block counts will be displayed in units of that block size. If BLOCKSIZE is not set, and the -h, -k or -m options are not specified, the block counts will be displayed in 512-byte blocks.
Show disk usage for all files in the current directory. Output is in human-readable form:
# du -ah
Summarize disk usage in the current directory:
# du -hs
Summarize disk usage for a specific directory:
# du -hs /home
Show name and size of all C files in a specific directory. Also display a grand total at the end:
# du -ch /usr/src/sys/kern/*.c
A du command appeared in AT&T v1 .