NAME¶
snooper
—
a utility for capturing data flowing between serial
devices
SYNOPSIS¶
snooper |
[ -b
baudrate ]
[-t ]
[-u ]
[-x ]
[-n ]
port0
port1 |
DESCRIPTION¶
snooper
passes data transparently between two
serial (RS232C) devices, capturing and logging the data and occasional
comments you want to insert into the logs.
It is useful for debugging or analyzing the communications protocol between two
devices that would normally be connected directly to each other, e.g. a
digital camera and a personal computer. By sitting in the middle (after you
connect the two devices to serial ports on your Linux machine) snooper is able
to capture data traveling in either direction while also passing it unmodified
to the other device.
It is also possible to operate with a single serial device, using your console
and keyboard as the second device.
OPTIONS¶
-b
baudrate
- Specify baudrate to use. Default baudrate is 9600.
-t
- Include current time (in microseconds) with each write to the textual log
file. See L under KEYBOARD COMMANDS, below.
-u
- Do not perform serial device locking. (This option is discouraged, and
should never be necessary on a properly-configured Debian system.)
-x
- Hex display only. (Even printable characters will be displayed in
hex.)
-n
- Do not forward traffic between the two ports; useful when you have a
splitter cable.
-h
- Help; presents a brief synopsis of the command line options.
KEYBOARD COMMANDS¶
snooper
has a set of commands that act
similar to those of vi.
Note that the characters transmitted into the serial ports will not be forwarded
while
snooper
is in command parameter input
mode. You should therefore set the log file and so forth while the serial line
has no activity.
L
- Switch textual log file. You'll be asked to answer the filename of the log
file.
B
- Switch binary log file. You'll asked to answer which device to log, and
the log file name. Please note that the binary log will contain the input
from the perspective of
snooper.
Therefore, if you would like to make a log of input of line 0 (thus the
output from device connected to line 0), you shold specify line 0. You
should use a file that is local, or on a virtual disk, so that no
characters will be lost.
m
- add a memo line to the text log file. The memo line will contain a
timestamp and the text you provide.
Q
- Quit.
c
- Reset the counter.
b
- Change the baudrate.
C
- Make the console act as one of the serial lines.
ESC
Go back to command mode.
^V
Quote the next char (so that you can
send ESC
, for example).
^X
input a byte by its 2-character
hexadecimal value (so that you can send any character you like). By
tapping any other key, that character will be sent to the line.
^L
- Repaint the screen.
An unrecognized command character will present a brief list of the valid command
characters.
EXAMPLE¶
snooper /dev/ttyS0
/dev/ttyS1
AUTHOR¶
Jun-ichiro Itoh <itojun@itojun.org>
This man page was written by David Coe <davidc@debian.org> for the Debian
project, and may be used by others under the terms of the GNU General Purpose
License, version 2 or later.