-b
Output in bytes
-k
Output in kilobytes
-m
Output in megabytes
date [options]
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
the date(1) man page.
17.12.2.2 Processes
top [options]
top provides a quick overview of the currently running processes. Press [H] to
access a page that briey explains the main options for customizing the program.
ps [options] [process_ID]
If run without any options, this command displays a table of all your own programs
or processes—those you started. The options for this command are not preceded
by hyphen.
aux
Displays a detailed list of all processes, independent of the owner
kill [options] process_ID
Unfortunately, sometimes a program cannot be terminated in the normal way.
In most cases, you should still be able to stop such a runaway program by exe-
cuting the kill command, specifying the respective process ID (see top and ps).
kill sends a TERM signal that instructs the program to shut itself down. If this
does not help, the following parameter can be used:
-9
Sends a KILL signal instead of a TERM signal, bringing the specied process
to an end in almost all cases
killall [options] processname
This command is similar to kill, but uses the process name (instead of the process
ID) as an argument, killing all processes with that name.
17.12.2.3 Network
ping [options] hostname_or_IP address
The ping command is the standard tool for testing the basic functionality of TCP/IP
networks. It sends a small data packet to the destination host, requesting an im-
mediate reply. If this works, ping displays a message to that eect, which indicates
that the network link is basically functioning.
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