Man page of bwm-ng
Section: Bandwidth Monitor NG (1)
Return to Main Contents
bwm-ng - Bandwidth Monitor NG (Next Generation), a live bandwidth monitor for network and disk io.
bwm-ng [options] ... [configfile]
can be used to monitor the current bandwidth of all or some specific
network interfaces or disks (or partitions). It shows
total of in and out as well as total of all interfaces/devices. Several
different output methods are supported (curses, curses2, plain, csv and html).
bwm-ng is not limited in the number of interfaces or disks and can handle
new ones dynamically while its running or hide those which are not up.
The input methods used pretty much depends on your OS and system.
You can choose the preferred method either at start or in curses during run-time.
Each method can only be used if
was compiled with support for it.
network input methods:
- proc :
This is the default for Linux based systems. It parses the special
procfs file /proc/net/dev. This should be used if in doubt in
- getifaddrs :
This is the default on BSD systems like FreeBSD, NetBSD,
OpenBSD and recent Mac OS X (>=10.3). This should be used if in
doubt on those systems. It uses the getifaddrs systemcall.
- kstat :
This is the default for Solaris. It uses the kstat systemcall.
- sysctl :
This is the default on Systems like IRIX and other UNIX. It can
be used on many other systems like early Mac OS X as well. It uses the
- netstat :
This is a Backup for systems without the above, or other problems.
- libstatgrab :
can use the external library libstatgrab to gather the data. please
refer to http://www.i-scream.org/libstatgrab for more info about
disk input methods:
Shows the diskio on Linux 2.6+ systems using /proc/diskstats. Instead of packets
the number of read/writes will be shown.
network input but for disk io. It uses the kstat systemcall from Solaris.
Written for NetBSD and OpenBSD, but maybe working on other Platforms
devstat library based input. You can find this on FreeBSD based systems.
framework IOKit based input. You can find this on Darwin systems like MacOSX.
but for disk io (http://www.i-scream.org/libstatgrab/).
You can select several different ways to output the data gathered by
You can use one of:
This is the default output method. Usually this fits you the most.
In curses mode you can control bwm-ng with several keys.
Press 'h' for a online help. To quit using this mode either press 'q'
Shows bar charts of the current IO, using curses output.
Plain or ASCII is mostly a backup if curses is not
available. You cannot control bwm-ng at all in this mode. To
quit press ctrl-c.
But for one single single output using
this is the mode that fits the best.
CSV is designed to use with scripts for easy parsing. For a list
of those elements please take a look at README - Specs section.
To skip the first output with only zeros use
bwm-ng -o csv -c 0
This is designed for use in the WWW. It uses the CSS file bwm-ng.css in
current working dir. "--htmlrefresh" only affects the refresh of the page
by the browser. For best results use the same value for --timeout and
The options that are recognized by
can be divided into 3 different groups. The long versions can only be used
if bwm-ng was compiled with getopt_long.
These options specify the method to gather the data as well as different
options for them.
- -i, --input method
selects which method to use. It can be one of the above (see
INPUT METHODS) if support for it was compiled in.
- -f, --procfile filename
selects the file to parse in proc input method. This is usually
- --diskstatsfile filename
selects the file to parse in disk input method. This is usually
- --partitionsfile filename
selects the file to parse in disk input method on older Kernel.
This is usually /proc/partitions.
- -n, --netstat path
specifies the binary to execute for netstat input method. Because
this may be a security flaw support for this option is not compiled
These options select the way to output the data and several options for
- -o, --output method
selects which method to use for output. It can be one of the above (see
OUTPUT METHODS) if support for it was compiled in.
- -u, --unit value
selects which unit to show. It can be one of bytes, bits,
packets or errors.
- -T, --type value
specifies the type of stats to show. Use one of rate for the current
rate/s, max for the maximal value achieved since startup of
bwm-ng, sum for the total sum counted since startup of
bwm-ng or avg for the average over the last 30 seconds.
- -c, --count number
number of outputs for Plain and CSV output mode. Use '1' for
once single output. Using '0' in CSV mode will skip first output
that always consists of zero values.
- -C, --csvchar char
specifies the delimiter char for CSV mode. The default is ';'.
- -F, --outfile filename
specifies the use of a outfile instead of stdout. This option
only affects CSV and HTML mode.
- -R, --htmlrefresh seconds
sets the HTML Meta refresh field to seconds in HTML mode.
This will result in a reload of the page every n seconds by
the browser. If this is set you want to use --htmlheader as well.
- -H, --htmlheader [value]
if this option is used, bwm-ng will print the correct HTML
header (<html></html>) including Meta fields before and after data.
This is only useful in HTML mode. value can be 0 (off)
or 1 (on), if the value is not given '1' is used.
- -N, --ansiout
disable ANSI Codes for Plain output.
show long realnames of disks in Darwin (ioservice input)
These options specify the general behavior of bwm-ng.
- -t, --timeout msec
displays and gathers stats every n msec (1msec = 1/1000sec). The
default is 500msec.
- -d, --dynamic [value]
shows bytes and bits with dynamic unit like K, M or G (Kilo, Mega, Giga).
value can be 0 (off) or 1 (on), without a value '1' is used.
- -a, --allif [mode]
specifies whether only up and selected interfaces (mode=0), all which
are up but maybe not selected (mode=1) or all, even down and not
selected interfaces (mode=2). If no interface list given
(--interfaces) mode=1 and mode=2 are the same.
- -I, --interfaces list
show only interfaces which are in this comma separated list (whitelist).
If the list is prefixed by a '%' its meaning is negated and interfaces in this
list are hidden from output (blacklist). (Example: %eth0,tun0)
- -S, --sumhidden [value]
if given and the optional value is not 0, count also hidden and not shown
interfaces for total value.
- -A, --avglength seconds
sets the span in which the stats for average mode are collected. Default
is 30 seconds or 2*timeout.
- -D, --daemon [value]
fork into background and daemonize if given and the optional value is not 0.
This only affects HTML and CSV mode and --outfile is
- -h, --help
show a help of command line options.
- -V, --version
print version info
The behavior of bwm-ng can be also controlled by a configfile.
By default bwm-ng first reads /etc/bwm-ng.conf and then
~/.bwm-ng.conf. If specified on command line bwm-ng skips those.
It consists of the same long-options as used for command line as keys
followed by a '=' and the value. Lines starting with a # or unknown
key will be ignored.
the CSS file used for html output.
bwm-ng.conf-example for an example of the configfile, README for other
comments and hints about bwm-ng.
http://www.gropp.org/ for new version or further help and links.
Volker Gropp <[email protected]> wrote bwm-ng and is current maintainer.
For further Authors please refer to AUTHORS file which should come
- INPUT METHODS
- OUTPUT METHODS
- OTHER FILES
- SEE ALSO
This document was created by
using the manual pages.
Time: 03:41:09 GMT, September 24, 2010