Provided by: picocom_2.2-2_amd64 
NAME
picocom - minimal dumb-terminal emulation program
SYNOPSIS
picocom [ options ] device
DESCRIPTION
As its name suggests, picocom(1) is a minimal dumb-terminal emulation program. It is, in
principle, very much like minicom(1), only it's "pico" instead of "mini"! It was designed
to serve as a simple, manual, modem configuration, testing, and debugging tool. It has
also served (quite well) as a low-tech serial communications program to allow access to
all types of devices that provide serial consoles. It could also prove useful in many
other similar tasks.
When picocom starts it opens the terminal (serial device) given as its non-option
argument. Unless the --noinit option is given, it configures the device to the settings
specified by the option-arguments (or to some default settings), and sets it to "raw"
mode. If --noinit is given, the initialization and configuration is skipped; the device
is just opened. Following this, picocom sets the standard-input and standard-output to
raw mode. Having done so, it goes in a loop where it listens for input from stdin, or
from the serial port. Input from the serial port is copied to the standard output while
input from the standard input is copied to the serial port. Picocom also scans its input
stream for a user-specified control character, called the escape character (being by
default C-a). If the escape character is seen, then instead of sending it to the
serial-device, the program enters "command mode" and waits for the next character (which
is called the "function character"). Depending on the value of the function character,
picocom performs one of the operations described in the COMMANDS section below.
COMMANDS
Commands are given to picocom by first keying the espace character which by default is C-a
(see OPTIONS below for how to change it), and then keying one of the function (command)
characters shown here.
escape character
Send the escape character to the serial port and return to "transparent" mode.
This means that if the escape character (C-a, by default) is typed twice, the
program sends the escape character to the serial port, and remains in transparent
mode.
C-x Exit the program: if the --noreset option was not given then the serial port is
reset to its original settings before exiting; if it was given the serial port is
not reset.
C-q Quit the program without reseting the serial port, regardless of the --noreset
option.
C-p Pulse the DTR line. Lower it for 1 sec, and then raise it again.
C-t Toggle the DTR line. If DTR is up, then lower it. If it is down, then raise it.
C-backslash
Generate a break sequence on the serial line. A break sequence is usually
generated by marking (driving to logical one) the serial Tx line for an amount of
time coresponding to several character durations.
C-b Set baurdate. Prompts you to enter a baudrate numerically (in bps) and configures
the serial port accordingly.
C-u Baud up. Increase the baud-rate. The list of baud-rates stepped-through by this
command is: 50, 75, 110, 134, 150, 200, 300, 600, 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200. If HIGH_BAUD support is compiled-in, then the following
baud-rates are also added to the list: 230400, 460800, 500000, 576000, 921600,
1000000, 1152000, 1500000, 2000000, 2500000, 3000000, 3500000, 4000000. Depending
on you system, any of the higher baud rates may be missing.
C-d Baud down. Decrease the baud-rate. The list of baud-rates stepped-through by this
command is the same as for the "baud-up" command.
C-f Cycle through flow-control settings (RTS/CTS, XON/XOFF, none).
C-y Cycle through parity settings (even, odd, none).
C-i Cycle through databits-number settings (5, 6, 7, 8).
C-j Cycle through stopbits-number settings (1, 2).
C-c Toggle local-echo mode.
C-v Show program options (like baud rate, data bits, etc) as well as the actual serial
port settings. Only the options and port settings that can be modified online
(through commands) are shown, not those that can only be set at the command-line.
See DISPLAY OF OPTIONS AND PORT SETTINGS for details.
C-h or C-k
Show help or show keys. Prints a short description of all available function
(command) keys.
C-s Send (upload) a file. See SENDING AND RECEIVING FILES below.
C-r Receive (download) a file. See SENDING AND RECEIVING FILES below.
After performing one of the above operations, the program leaves the command mode and
enters transparent mode. Example: To increase the baud-rate by two steps, you have to
type:
C-a, C-u, C-a, C-u
assuming of-course that C-a is the escape character.
OPTIONS
Picocom accepts the following command-line options.
--baud | -b
Defines the baud-rate to set the serial-port (terminal) to.
--flow | -f
Defines the flow-control mode to set the serial-port to. Must be one of: x for
xon/xoff (software) mode, h for hardware flow control (RTS/CTS), n for no flow
control. (Default: n)
--parity | -y
Defines the parity mode to set the serial-port to. Must be one of: o for odd
parity mode, e for even parity mode, n for no parity mode. (Default: n)
--databits | -d
Defines the number of data bits in every character. Must be one of: 5, 6, 7, 8.
(Default: 8)
--stopbits | -p
Defines the number of stop bits in every character. Must be one of: 1, or 2.
(Default: 1)
--escape | -e
Defines the character that will make picocom enter command-mode (see description
above). If x is given, then C-x will make picocom enter command mode. (Default:
a)
--echo | -c
Enable local echo. Every character being read from the terminal (standard input)
is echoed to the terminal (standard output) subject to the echo-mapping
configuration (see --emap option). (Default: Disabled)
--noinit | -i
If given, picocom will not initialize, reset, or otherwise meddle with the serial
port at start-up. It will just open it. This is useful, for example, for
connecting picocom to already-connected modems, or already configured ports without
terminating the connection, or altering the settings. If required, serial port
parameters can then be adjusted at run-time by commands. (Default: Disabled)
--noreset | -r
If given, picocom will not reset the serial port when exiting. It will just close
the filedes and do nothing more. This is useful, for example, for leaving modems
connected when exiting picocom. Regardless whether the --noreset option is given,
the user can exit picocom using the "Quit" command (instead of "Exit"), which never
resets the serial port. If --noreset is given then "Quit" and "Exit" behave
essentially the same. (Default: Disabled)
--nolock | -l
If given, picocom will not attempt to lock the serial port before opening it.
Normally, depending on how it's compiled, picocom attempts to get a UUCP-style
lock-file (e.g. '/var/lock/LCK..ttyS0') before opening the port, or attempts to
lock the port device-node using flock(2). Failing to do so, results in the program
exiting after emitting an error-message. It is possible that your picocom binary
is compiled without support for locking. In this case the --nolock option is
accepted, but has no effect. (Default: Disabled)
--send-cmd | -s
Specifies the external program (and any arguments to it) that will be used for
transmitting files. If the argument to --send-cmd is the empty string (''), the
send-file command is disabled. See SENDING AND RECEIVING FILES. (Default: sz -vv)
--receive-cmd | -v
Specifies the external program (and any arguments to it) that will be used for
receiving files. If the argument to --receive-cmd is the empty string (''), the
receive-file command is disabled. See SENDING AND RECEIVING FILES. (Default: rz
-vv)
--imap Specifies the input character map (i.e. special characters to be replaced when
read from the serial port). See INPUT, OUTPUT, AND ECHO MAPPING. (Defaul: Empty)
--omap Specifies the output character map (i.e. special characters to be replaced before
being written to serial port). See INPUT, OUTPUT, AND ECHO MAPPING. (Defaul:
Empty)
--emap Specifies the local-echo character map (i.e. special characters to be replaced
before being echoed-back to the terminal, if local-echo is enabled). See INPUT,
OUTPUT, AND ECHO MAPPING. (Defaul: delbs,crcrlf)
--help | -h
Print a short help message describing the command-line options. Picocom's version,
ompile-time options, and enabled features are also shown.
DISPLAY OF OPTIONS AND PORT SETTINGS
The "show program options" command (C-v), as well as the commands that change program
options (C-b, C-u, C-d, C-f, etc) print messages showing the current values (or the new
values, if they were changed) for the respective options. If picocom determines that an
actual serial-port setting differs from the current value of the respective option (for
whatever reason), then the value of the option is shown followed by the value of the
actual serial-port setting in parenthesis. Example:
*** baud: 115200 (9600)
This means that a baud rate of 115200bps has been selected (from the command line, or
using commands that change the baudrate) but the serial-port is actually operating at
9600bps (the driver may not support the higher setting, and has silently replaced it with
a safe default, or the setting may have been changed from outside picocom). If the option
and the corresponding serial-port setting are the same, only a single value is shown.
Example:
*** baud: 9600
This behavioir was intriduced in picocom 2.0. Older releases displayed only the option
values, not the actual serial-port settings corresponding to them.
SENDING AND RECEIVING FILES
Picocom can send and receive files over the serial port using external programs that
implement the respective protocols. In Linux typical programs for this purpose are:
• rx(1) - receive using the X-MODEM protocol
• rb(1) - receive using the Y-MODEM protocol
• rz(1) - receive using the Z-MODEM protocol
• sx(1) - send using the X-MODEM protocol
• sb(1) - send using the Y-MODEM protocol
• sz(1) - send using the Z-MODEM protocol
• ascii-xfr(1) - receive or transmit ASCII files
The name of, and the command-line options to, the program to be used for transmitting
files are given by the --send-cmd option. Similarly the program to receive files, and its
argumets, are given by the --receive-cmd option. For example, in order to start a picocom
session that uses sz(1) to transmit files, and rz(1) to receive files, you have to say
something like this:
picocom --send-cmd "sz -vv" --receive-cmd "rz -vv" ...
If the argument to the -send-cmd option, or the argument to the --receive-cmd option is
the empty string, then the respective command is disabled. For example, in order to
disable both the "send" and the "receive" commands you can invoke picocom like this:
picocom --send-cmd '' --receive-cmd '' ...
A picocom session with both, the send- and the receive-file commands disabled does not
fork(2) and does not run any external programs.
During the picocom session, if you key the "send" or "receive" commands (e.g. by pressing
C-a, C-s, or C-a, C-r) you will be prompted for a filename. At this prompt you can enter
one or more file-names, and any additional arguments to the transmission or reception
program. Command-line editing and rudimentary pathname completion are available at this
prompt, if you have compiled picocom with support for the linenoise library. Pressing C-c
at this prompt will cancel the file transfer command and return to normal picocom
operation. After entering a filename (and / or additional transmission or reception
program arguments) and assuming you have not canceled the operation by pressing C-c,
picocom will start the the external program as specified by the --send-cmd, or
--receive-cmd option, and with any filenames and additional arguments you may have
supplied. The standard input and output of the external program will be connected to the
serial port. The standard error of the external program will be connected to the terminal
which---while the program is running---will revert to canonical mode. Pressing C-c while
the external program is running will prematurely terminate it (assuming that the program
itself does not ignore SIGINT), and return control to picocom. Pressing C-c at any other
time, has no special effect; the character is normally passed to the serial port.
INPUT, OUTPUT, AND ECHO MAPPING
Using the --imap, --omap, and --emap options you can make picocom map (tranlate, replace)
certain special characters after being read from the serial port (with --imap), before
being written to the serial port (with --omap), and before being locally echoed to the
terminal (standard output) if local echo is enabled (with --emap). These mapping options
take, each, a single argument which is a comma-separated list of one or more of the
following identifiers:
• crlf (map CR to LF),
• crcrlf (map CR to CR + LF),
• igncr (ignore CR),
• lfcr (map LF to CR),
• lfcrlf (map LF to CR + LF),
• ignlf (ignore LF),
• bsdel (map BS to DEL),
• delbs (map DEL to BS)
For example the command:
picocom --omap crlf,delbs --imap inglf,bsdel --emap crcrlf ...
will:
• Replace every CR (carriage return, 0x0d) caracter with LF (line feed, 0x0a) and every
DEL (delete, 0x7f) character with BS (backspace, 0x08) before writing it to the serial
port.
• Ignore (not write to the terminal) every LF character read from the serial port, and
replace every BS character read from the serial port with DEL.
• Replace every CR character with CR and LF when echoing to the terminal (if local-echo is
enabled).
AUTHOR
Written by Nick Patavalis <npat@efault.net>
AVAILABILITY
Download the latest release from: <https://github.com/npat-efault/picocom/releases>
COPYRIGHT
Copyright (c) 2004-2016 Nick Patavalis
This file is part of Picocom.
Picocom is free software; you can redistribute it and/or modify it under the terms of the
GNU General Public License as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
Picocom is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program;
if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA