ttyplot.1

.Dd June 23, 2026
.Dt TTYPLOT 1
.Os
.Sh NAME
.Nm ttyplot
.Nd realtime terminal plotting utility
.Sh SYNOPSIS
.Nm
.Op Fl 2bBfr
.Op Fl c Ar plotchar
.Op Fl e Ar errcharmax
.Op Fl E Ar errcharmin
.Op Fl s Ar softmax
.Op Fl S Ar softmin
.Op Fl m Ar hardmax
.Op Fl M Ar hardmin
.Op Fl t Ar title
.Op Fl u Ar unit
.Op Fl C Ar colorspec
.Nm
.Fl v
.Nm
.Fl h
.Sh DESCRIPTION
.Nm
takes data from standard input,
most commonly some tool like
.Xr ping 1 ,
.Xr snmpget 1 ,
.Xr netstat 8 ,
.Xr ifconfig 8 ,
.Xr sar 1 ,
.Xr vmstat 8 ,
etc.,
and plots in text mode on a terminal in real time.
.Pp
Supports rate calculation for counters and up to two graphs
on a single display, using reverse video for the second line
or, experimentally, braille or block element line drawing in color.
.Pp
The following options are supported:
.Bl -tag -width Ds
.It Fl 2
Read two values and draw two plots, the second in reverse video.
.It Fl b
.Pq Experimental
Use braille line drawing instead of block/reverse-video bars.
With
.Fl 2 ,
the two lines are distinguished by color rather than reverse video.
Requires a UTF-8 locale and a capable font, otherwise falls back.
.It Fl B
.Pq Experimental
Use block element (quadrant) line drawing, like
.Fl b .
.It Fl f
.Pq Experimental
Fill the area under the line in braille or block mode
.Pq line 1 .
.It Fl r
Calculate counter rate and divide by measured sample interval.
.It Fl c Ar plotchar
Use
.Ar plotchar
for the plot line, e.g.
.Ql @ # % \&.
etc.
.It Fl e Ar errcharmax
Use
.Ar errcharmax
for plot error line when value exceeds hardmax.
Default:
.Ql e .
.It Fl E Ar errcharmin
Use
.Ar errcharmin
for plot error symbol, displayed when plot value is less than hardmin.
Default:
.Ql v .
.It Fl s Ar softmax
Use
.Ar softmax
as the initial maximum value but allow it to grow with input.
.It Fl S Ar softmin
Use
.Ar softmin
as the initial minimum value but allow it to shrink with input.
.It Fl m Ar hardmax
Use
.Ar hardmax
as a hard value limit after which an error line will be drawn
.Po
see
.Fl e
.Pc . Should be greater than hardmin, if set.
.It Fl M Ar hardmin
Use
.Ar hardmin
as a definite minimum limit of the plot range. If a plot value is less than this, error symbol will be drawn
.Po
see
.Fl E
.Pc .
.It Fl t Ar title
Use
.Ar title
as the plot title.
.It Fl u Ar unit
Label the vertical axis
.Ar unit .
.It Fl C Ar colorspec
Set colors for plot elements.
.Ar colorspec
is either a predefined scheme name or a comma-separated list of
color numbers
.Pq Ar 0-7 :
.Ar plotchar Ns Op / Ns Ar line2 ,
.Ar axes ,
.Ar text ,
.Ar title ,
.Ar max_err ,
.Ar min_err .
Only the first value, the plot line color, is required; the rest
are optional.
The optional
.Ar line2
sets the second line color in braille or block mode.
For example
.Ql Fl C Ar 1,2,3,4,5,6 ,
.Ql Fl C Ar 1,2
or
.Ql Fl C Ar 1 .
The color numbers are
.Ar 0
black,
.Ar 1
red,
.Ar 2
green,
.Ar 3
yellow,
.Ar 4
blue,
.Ar 5
magenta,
.Ar 6
cyan and
.Ar 7
white.
Alternatively,
.Ar colorspec
may name a predefined scheme:
.Ar dark1
or
.Ar dark2
for dark terminals,
.Ar light1
or
.Ar light2
for light terminals.
.It Fl v
Print the current version and exit.
.It Fl h
Print this help message and exit.
.El
.Sh KEY BINDINGS
When reading data from a pipe,
.Nm
accepts the following commands typed at the terminal:
.Bl -tag -width Ds
.It Ic q
Quit.
.It Ic r
Toggle "rate mode" on and off.
.It Ic Ctrl-L
Full screen redraw.
.El
.Pp
These commands do not work when standard input is a terminal;
in that case quit with
.Ql Ctrl-C .
.Sh EXAMPLES
CPU usage from
.Xr vmstat 8
using
.Xr awk 1
to pick the right column:
.Bd -literal -offset indent
vmstat -n 1 \\
 | gawk '{ print 100-int($(NF-2)); fflush(); }' \\
 | ttyplot
.Ed
.Pp
CPU usage from
.Xr sar 1
with title and fixed scale to 100%:
.Bd -literal -offset indent
sar 1 \\
 | gawk '{ print 100-int($NF); fflush(); }' \\
 | ttyplot -s 100 -t "cpu usage" -u "%"
.Ed
.Pp
Memory usage from
.Xr sar 1 ,
using
.Xr perl 1 ,
to pick the right column:
.Bd -literal -offset indent
sar -r 1 \\
 | perl -lane 'BEGIN{$|=1} print "@F[5]"' \\
 | ttyplot -s 100 -t "memory used %" -u "%"
.Ed
.Pp
Number of processes in running and io blocked state:
.Bd -literal -offset indent
vmstat -n 1 \\
 | perl -lane 'BEGIN{$|=1} print "@F[0,1]"' \\
 | ttyplot -2 -t "procs in R and D state"
.Ed
.Pp
Load average via
.Xr uptime 1 and
.Xr awk 1 :
.Bd -literal -offset indent
{ while true; do
    uptime | gawk '{ gsub(/,/, ""); print $(NF-2) }'
    sleep 1
  done } | ttyplot -t "load average" -s load
.Ed
.Pp
Ping plot with
.Xr sed 1 :
.Bd -literal -offset indent
ping 8.8.8.8 \\
 | sed -u 's/^.*time=//g; s/ ms//g' \\
 | ttyplot -t "ping to 8.8.8.8" -u ms
.Ed
.Pp
The same ping plot, drawn with braille
.Pq see Fl b :
.Bd -literal -offset indent
ping 8.8.8.8 \\
 | sed -u 's/^.*time=//g; s/ ms//g' \\
 | ttyplot -b -t "ping to 8.8.8.8" -u ms
.Ed
.Pp
The same ping plot, with custom colors for the line, axes, text
and title
.Pq see Fl C :
.Bd -literal -offset indent
ping 8.8.8.8 \\
 | sed -u 's/^.*time=//g; s/ ms//g' \\
 | ttyplot -t "ping to 8.8.8.8" -u ms -C 2,3,4,5
.Ed
.Pp
WiFi signal level in -dBM (higher is worse) using
.Xr iwconfig 8 :
.Bd -literal -offset indent
{ while true; do
    iwconfig 2>/dev/null \\
     | grep "Signal level" \\
     | sed -u 's/^.*Signal level=-//g; s/dBm//g'
    sleep 1
  done } | ttyplot -t "wifi signal" -u "-dBm" -s 90
.Ed
.Pp
CPU temperature from proc;
.Bd -literal -offset indent
{ while true; do
    awk '{ printf("%.1f\n", $1/1000) }' \\
         /sys/class/thermal/thermal_zone0/temp
    sleep 1
  done } | ttyplot -t "cpu temp" -u C
.Ed
.Pp
Fan speed from
.Xr sensors 1
using
.Xr grep 1 ,
.Xr tr 1
and
.Xr cut 1 :
.Bd -literal -offset indent
{ while true; do
    sensors | grep fan1: | tr -s " " | cut -d" " -f2
    sleep 1
  done } | ttyplot -t "fan speed" -u RPM
.Ed
.Pp
Bitcoin price chart using
.Xr curl 1
and
.Xr jq 1 :
.Bd -literal -offset indent
{ while true; do
    curl -sL https://api.coindesk.com/v1/bpi/currentprice.json \\
     | jq .bpi.USD.rate_float
    sleep 600
  done } | ttyplot -t "bitcoin price" -u usd
.Ed
.Pp
Stock quote chart:
.Bd -literal -offset indent
{ while true; do
    curl -sL https://api.iextrading.com/1.0/stock/googl/price
    echo
    sleep 600
  done } | ttyplot -t "google stock price" -u usd
.Ed
.Pp
Prometheus load average via
.Ic node_exporter :
.Bd -literal -offset indent
{ while true; do
    curl -s  http://10.4.7.180:9100/metrics \\
     | grep "^node_load1 " \\
     | cut -d" " -f2; sleep 1
  done } | ttyplot
.Ed
.Ss Network/disk throughput examples
.Nm
supports two-line plots for in/out or read/write.
.Pp
Local network throughput for all interfaces combined from
.Xr sar 1 :
.Bd -literal -offset indent
sar -n DEV 1 | gawk '{
  if($6 ~ /rxkB/) {
     print iin/1000;
     print out/1000;
     iin=0;
     out=0;
     fflush();
  }
  iin=iin+$6;
  out=out+$7;
}' | ttyplot -2 -u "MB/s"
.Ed
.Pp
SNMP network throughput for an interface using
.Ql ttg :
.Bd -literal -offset indent
ttg -i 10 -u Mb 10.23.73.254 public 9 \\
 | gawk '{ print $5,$8; fflush(); }' \\
 | ttyplot -2 -u Mb/s
.Ed
.Pp
SNMP network throughput for an interface using
.Xr snmpdelta 1 :
.Bd -literal -offset indent
snmpdelta -v 2c -c public -Cp 10 \\
          10.23.73.254 1.3.6.1.2.1.2.2.1.{10,16}.9 \\
 | gawk '{ print $NF/1000/1000/10; fflush(); }' \\
 | ttyplot -2 -t "interface 9 throughput" -u Mb/s
.Ed
.Pp
Disk throughput from
.Xr iostat 1 :
.Bd -literal -offset indent
iostat -xmy 1 nvme0n1 \\
 | stdbuf -o0 tr -s " " \\
 | stdbuf -o0 cut -d " " -f 4,5 \\
 | ttyplot -2 -t "nvme0n1 throughput" -u MB/s
.Ed
.Ss Rate calculator for counters
.Nm
also supports counter style metrics,
calculating a rate by measuring time difference between samples.
.Pp
SNMP network throughput for an interface using
.Xr snmpget 1 :
.Bd -literal -offset indent
{ while true; do
    snmpget  -v 2c -c public \\
             10.23.73.254 1.3.6.1.2.1.2.2.1.{10,16}.9 \\
     | awk '{ print $NF/1000/1000; }'
    sleep 10
  done } | ttyplot -2 -r -u "MB/s"
.Ed
.Pp
Local interface throughput using
.Xr ip 8
and
.Xr jq 1 :
.Bd -literal -offset indent
{ while true; do
    ip -s -j link show enp0s31f6 \\
     | jq '.[].stats64.rx.bytes/1024/1024, \\
           .[].stats64.tx.bytes/1024/1024'
    sleep 1
  done } | ttyplot -r -2 -u "MB/s"
.Ed
.Pp
Prometheus node exporter disk throughput for
.Pa /dev/sda :
.Bd -literal -offset indent
{ while true; do
    curl -s http://10.11.0.173:9100/metrics \\
     | awk '/^node_disk_.+_bytes_total{device="sda"}/ {
         printf("%f\n", $2/1024/1024);
       }'
    sleep 1
  done } | ttyplot -r -2 -u MB/s -t "10.11.0.173 sda writes"
.Ed
.Sh AUTHORS
.Nm
is written by:
.br
.An Antoni Sawicki Aq Mt tenox@google.com ,
.An Edgar Bonet Aq Mt linux@edgar-bonet.org
and
.An Sebastian Pipping Aq Mt sebastian@pipping.org .
.Pp
Its readme was converted into this manual page by
.An Sijmen J. Mulder Aq Mt ik@sjmulder.nl .
.Sh BUGS
By default standard input and output are buffered.
This can be worked around in various
.Lk http://www.perkin.org.uk/posts/how-to-fix-stdio-buffering.html ways .
.Pp
When there is no more data,
.Nm
prints
.Dq input stream closed
and waits rather than quitting
.Pq prior to version 1.5 it quit .
The screen is normally erased on exit because of the terminal's
.Lk https://invisible-island.net/xterm/xterm.faq.html#xterm_tite "alternate screen" ;
this can be worked around, for example:
.Pp
.Dl echo 1 2 3 | TERM=vt100 ttyplot
.Pp
When running interactively and non-numeric data is entered
.Pq e.g. some key
.Nm
hangs.
Press
.Ql Ctrl^J
to reset.