topless(1) - Linux man page

Name

topless - display command output on the whole screen like "top"

Synopsis

topless [-cwVhv] [-s seconds] [-n number] [-a command] COMMAND

Description

topless reads various command output, displays it on the whole screen (like less), and periodically updates it like top.

topless can be used with almost every sort of command, but is particularly useful when used with the command to monitor the system, such as ps, netstat or fstat. See EXAMPLES below for details.

Options

-c The lines difference from the previous screen update are colorized. (default: false)
-s seconds: Set the screen update periods to seconds seconds. If the sleep(1) command accepts and honors a non-integer number of seconds, seconds can be a non-integer number. (default: 1)
-n number: The lines are kept colorized for number times screen update when -c is also enabled. Once a line is colorized, that line becomes blue on next screen update, and remains blue until the line returns to be original color. (default: 1)
-a command: Topless enforce the specified command when COMMAND output gets difference from the previous output assumed for alert use, instead of -c use for monochrome monitor or others. (default: false)
-w Topless will use as many columns as necessary without regard for your window size. (default: true) -V Topless gets information header. (default: false) -h Print help message. -v Print version.

Key Command

q quit topless

Examples

Display the output of "ps axuww" like top:

% topless ps axuww

Same as the above, but the lines difference from the previous screen update are colorized.

% topless -c ps axuww

Set the screen update periods to 0.1 seconds (suppose the sleep(1) command can honor non-integer number of seconds):

% topless -s 0.1 ps axuww

Once a line is colorized, that line becomes blue on next screen update, and remains blue after the next 10 times update:

% topless -c -n 10 netstat -a

COMMAND can be a more complex one, such as the one that contains pipe:

% topless 'fstat -f /var| sort -k8 -nr'

% topless -c 'sockstat | egrep "([0-9]{1,3}[.]){3}[0-9]{1,3}"'

Display the outout of "ps axuww" like top with information header like watch(1) of Linux:

% topless -V ps axuww

Alert when /var/log/messages gets change:

% topless -a "tput bl" tail /var/log/messages

Alert when /var/log/messages gets change running as deamon mode:

# kldload speaker
# daemon topless -a "echo AAA > /dev/speaker" tail /var/log/messages > /dev/null

Authors

Daichi GOTO <daichi@FreeBSD.org>

KOMATSU Shinichiro <koma2@lovepeers.org> (documents)

Portability

topless can work on various platforms, and has been reported to work on the following platforms:

FreeBSD, NetBSD, OpenBSD, Linux, MacOS X, SuSE 9.1,
Solaris 10/8 (ksh is required)

If you find topless does not work on your platform, feel free to send a patch to the author. Your patch is *always* welcome. ;)

Caveats

Special care must be taken when you search about topless, especially when you are at your office or with your family, because the search results may not be what you expected.