Datasheet

21.3.2 System Commands
System Information
df [option(s)] [directory] The df (disk free) command, when used
without any options, displays information about the total disk space, the
disk space currently in use, and the free space on all the mounted drives. If
a directory is specified, the information is limited to the drive on which that
directory is located.
-H Shows the number of occupied blocks in gigabytes, megabytes, or kilo-
bytes — in human-readable format
-t Type of file system (ext2, nfs, etc.)
du [option(s)] [path] This command, when executed without any param-
eters, shows the total disk space occupied by files and subdirectories in the
current directory.
-a Displays the size of each individual file
-h Output in human-readable form
-s Displays only the calculated total size
free [option(s)] The command free displays information about RAM
and swap space usage, showing the total and the used amount in both cate-
gories.
-b Output in bytes
-k Output in kilobytes
-m Output in megabytes
date [option(s)] This simple program displays the current system time. If
run as root, it can also be used to change the system time. Details about
the program are available in date.
Processes
top [options(s)] top provides a quick overview of the currently running
processes. Press




H to access a page that briefly explains the main options to
customize the program.
276 21.3. Important Linux Commands