du stands for disk usage. As the name suggests ,du command is used to calculate or summarize the disk usage of file ,directories & file system in UNIX like operating system. Syntax: # du [OPTION]... [FILE]... # du [OPTION]... --files0-from=F From the syntax it is clear that du command expects options and file name as arguments. Though these arguments are not mandatory but are required for getting disk usage of specific files in specific formats. Input file names can also be read from a separate file.