bwm-ng - Bandwidth Monitor NG (Next Generation), a live bandwidth
monitor for network and disk io.
bwm-ng [options] ... [configfile]
bwm-ng 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
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
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 bwm-ng was compiled with
support for it.
Currently supported network input methods:
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 Linux.
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
This is the default for Solaris. It uses the kstat
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 sysctl systemcall.
This is a Backup for systems without the above, or other
bwm-ng can use the external library libstatgrab to gather
the data. please refer to http://www.i-
scream.org/libstatgrab for more info about this.
Currently supported 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.
same as kstat network input but for disk io. It uses the
kstat systemcall from Solaris.
Written for NetBSD and OpenBSD, but maybe working on other
devstat library based input. You can find this on FreeBSD
framework IOKit based input. You can find this on Darwin
systems like MacOSX.
same as libstatgrab but for disk io (http://www.i-
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’ or ctrl-c.
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 --htmlrefresh.
The options that are recognized by bwm-ng 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
selects the file to parse in disk input method. This is usually
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 in bwm-ng by default.
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.
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 required.
show a help of command line options.
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.
bwm-ng.css 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@example.com> wrote bwm-ng and is current maintainer.
For further Authors please refer to AUTHORS file which should come with