NAME

tio - a serial device I/O tool

SYNOPSIS

tio [<options>] <tty-device|profile|tid>

DESCRIPTION

tio is a serial device tool which features a straightforward command-line and configuration file interface to easily connect to serial TTY devices for basic I/O operations.

OPTIONS

-b, --baudrate <bps>

Set baud rate [bps] (default: 115200).

-d, --databits 5|6|7|8

Set data bits (default: 8).

-f, --flow hard|soft|none

Set flow control (default: none).

-s, --stopbits 1|2

Set stop bits (default: 1).

-p, --parity odd|even|none|mark|space

Set parity (default: none).

Note: With mark parity the parity bit is always 0. With space parity the parity bit is always 1. Not all platforms support mark and space parity.

-o, --output-delay <ms>

Set output delay [ms] inserted between each sent character (default: 0).

-O, --output-line-delay <ms>

Set output delay [ms] inserted between each sent line (default: 0).

--line-pulse-duration <duration>

Set the pulse duration [ms] of each serial port line using the following key value pair format in the duration field: <key>=<value>

Each key represents a serial line. The following keys are available:

-a, --auto-connect new|latest|direct

Automatically connect to serial device according to one of the following strategies:

--exclude-devices <pattern>

Exclude devices by pattern ('*' and '?' supported).

--exclude-drivers <pattern>

Exclude drivers by pattern ('*' and '?' supported).

--exclude-tids <pattern>

Exclude topology IDs by pattern ('*' and '?' supported).

-n, --no-reconnect

Do not reconnect.

This means that tio will exit if it fails to connect to device or an established connection is lost.

-e, --local-echo

Enable local echo.

-t, --timestamp

Enable line timestamp.

--timestamp-format <format>

Set timestamp format to any of the following timestamp formats:

--timestamp-timeout <ms>

Set timestamp timeout value in milliseconds.

This value only takes effect in hex output mode where timestamps are only printed after elapsed timeout time of no output activity from tty device.

Default value is 200.

-l, --list

List available targets (serial devices, TIDs, configuration profiles).

-L, --log

Enable log to file.

The log file will be automatically named using the following format tio_TARGET_YYYY-MM-DDTHH:MM:SS.log. Target being the command line target such as tty-device, tid, or configuration profile.

The filename can be manually set using the --log-file option.

--log-file <filename>

Set log filename.

--log-directory <path>

Set log directory path in which to save automatically named log files.

--log-append

Append to log file.

--log-strip

Strip control characters and escape sequences from log.

-m, --map <flags>

Map (replace, translate) characters on input to the serial device or output from the serial device. The following mapping flags are supported:

--input-mode normal|hex|line

Set input mode.

In normal mode input characters are sent immediately as they are typed.

In hex input mode bytes can be sent by typing the two-character hexadecimal representation of the 1 byte value, e.g.: to send 0xA you must type 0a or 0A.

In line input mode input characters are sent when you press enter. The only editing feature supported in this mode is backspace.

Default value is "normal".

--output-mode normal|hex|hexN

Set output mode.

In hex mode each incoming byte is printed out as a 1 byte hex value.

In hexN mode, N is a number less than or equal to 4096 which defines how many hex values will be printed before a line break.

Default value is "normal".

-c, --color 0..255|bold|none|list

Colorize tio text using ANSI color code value ranging from 0 to 255 or use "none" for no color or use "bold" to apply bold formatting to existing system color.

Use "list" to print a list of available ANSI color codes.

Default value is "bold".

-S, --socket <socket>

Redirect I/O to socket.

Any input from clients connected to the socket is sent on the serial port as if entered at the terminal where tio is running (except that ctrl-t sequences are not recognized), and any input from the serial port is multiplexed to the terminal and all connected clients.

Sockets remain open while the serial port is disconnected, and writes will block.

Various socket types are supported using the following prefixes in the socket field:

--rs-485

Enable RS-485 mode.

--rs-485-config <config>

Set the RS-485 configuration using the following key or key value pair format in the configuration field:

--alert none|bell|blink

Set alert action on connect/disconnect.

It will sound the bell once or blink once on successful connect. Likewise it will sound the bell twice or blink twice on disconnect.

Default value is "none".

--mute

Mute tio messages.

--script <string>

Run script from string.

--script-file <filename>

Run script from file with filename.

--script-run once|always|never

Run script on connect once, always, or never.

Default value is "always".

--exec <command>

Execute shell command with I/O redirected to device

-v, --version

Display program version.

-h, --help

Display help.

KEY COMMANDS

In session, all key strokes are forwarded to the serial device except the following key sequence: a prefix key (default: ctrl-t) followed by a command key. These sequences are intercepted as key commands:

ctrl-t ?

List available key commands

ctrl-t b

Send serial break (triggers SysRq on Linux, etc.)

ctrl-t c

Show configuration (baudrate, databits, etc.)

ctrl-t e

Toggle local echo mode

ctrl-t f

Toggle log to file

ctrl-t F

Flush data I/O buffers (discard data written but not transmitted and data received but not read)

ctrl-t g

Toggle serial port line

ctrl-t i

Toggle input mode

ctrl-t l

Clear screen

ctrl-t L

Show line states (DTR, RTS, CTS, DSR, DCD, RI)

ctrl-t m

Change mapping of characters on input or output

ctrl-t o

Toggle output mode

ctrl-t p

Pulse serial port line

ctrl-t q

Quit

ctrl-t r

Run script

ctrl-t R

Execute shell command with I/O redirected to device

ctrl-t s

Show TX/RX statistics

ctrl-t t

Toggle line timestamp mode

ctrl-t v

Show version

ctrl-t x

Send file using the XMODEM-1K or XMODEM-CRC protocol (prompts for file name and protocol)

ctrl-t y

Send file using the YMODEM protocol (prompts for file name)

ctrl-t ctrl-t

Send ctrl-t character

SCRIPT API

Tio suppots Lua scripting to easily automate interaction with the tty device.

In addition to the standard Lua API tio makes the following functions available:

expect(string, timeout)

Expect string - waits for string to match or timeout before continuing. Supports regular expressions. Special characters must be escaped with '\\'. Timeout is in milliseconds, defaults to 0 meaning it will wait forever.

Returns 1 on successful match, 0 on timeout, or -1 on error.

On successful match it also returns the match string as second return value.

read(size, timeout)

Read from serial device. If timeout is 0 or not provided it will wait forever until data is ready to read.

Returns number of bytes read on success, 0 on timeout, or -1 on error.

On success, returns read string as second return value. Also emits a single timestamp to stdout and log file per options.timestamp and options.log.

read_line(timeout)

Read line from serial device. If timeout is 0 or not provided it will wait forever until data is ready to read.

Returns number of bytes read on success, 0 on timeout, or -1 on error.

On success, returns the string that was read as second return value. Also emits a single timestamp to stdout and log file per options.timestamp and options.log.

write(string)

Write string to serial device.

Returns number of bytes written on success or -1 on error.

send(file, protocol)

Send file using x/y-modem protocol.

Protocol can be any of XMODEM_1K, XMODEM_CRC, YMODEM.

tty_search()

Search for serial devices.

Returns a table of number indexed tables, one for each serial device found. Each of these tables contains the serial device information accessible via the following string indexed elements "path", "tid", "uptime", "driver", "description".

Returns nil if no serial devices are found.

set{line=state, ...}

Set state of one or multiple tty modem lines.

Line can be any of DTR, RTS, CTS, DSR, CD, RI

State is high, low, or toggle.

sleep(seconds)

Sleep for seconds.

msleep(ms)

Sleep for milliseconds.

exit(code)

Exit with exit code.

CONFIGURATION FILE

Options can be set via configuration file using the INI format. tio uses the configuration file first found in the following locations in the order listed:

$XDG_CONFIG_HOME/tio/config

$HOME/.config/tio/config

$HOME/.tioconfig

Labels can be used to group settings into named configuration profiles which can be activated from the command-line when starting tio.

tio will try to match the user input to a configuration profile by name or by pattern to get the TTY device and other options.

Options without any label change the default options.

Any options set via command-line will override options set in the configuration file.

The following configuration file options are available:

pattern

Pattern matching user input. This pattern can be an extended regular expression with a single group.

device

TTY device to open. If it contains a "%s" it is substituted with the first group match.

baudrate

Set baud rate

databits

Set data bits

flow

Set flow control

stopbits

Set stop bits

parity

Set parity

output-delay

Set output character delay

output-line-delay

Set output line delay

line-pulse-duration

Set line pulse duration

no-reconnect

Do not reconnect

log

Enable log to file

log-file

Set log filename

log-directory

Set log directory path in which to save automatically named log files.

log-append

Append to log file

log-strip

Enable strip of control and escape sequences from log

local-echo

Enable local echo

timestamp

Enable line timestamp

timestamp-format

Set timestamp format

timestamp-timeout

Set timestamp timeout

map

Map characters on input or output

color

Colorize tio text using ANSI color code ranging from 0 to 255

input-mode

Set input mode

output-mode

Set output mode

socket

Set socket to redirect I/O to

prefix-ctrl-key

Set prefix ctrl key (a..z or 'none', default: t)

rs-485

Enable RS-485 mode

rs-485-config

Set RS-485 configuration

alert

Set alert action on connect/disconnect

mute

Mute tio messages

script

Run script from string

script-file

Run script from file

script-run

Run script on connect

exec

Execute shell command with I/O redirected to device

It is possible to include the content of other configuration files using the include directive like so: "[include <file>]".

CONFIGURATION FILE EXAMPLES

To change the default configuration simply set options like so:

[default]
baudrate = 9600
databits = 8
parity = none
stopbits = 1
color = 10
line-pulse-duration = DTR=200,RTS=400

Named configuration profiles can be added via labels:

[rpi3]
device = /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0
baudrate = 115200
color = 11

Activate the configuration profile by name:

$ tio rpi3

Which is equivalent to:

$ tio -b 115200 -c 11 /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0

A configuration profile can also be activated by its pattern which supports regular expressions:

[usb-devices]
pattern = ^usb([0-9]*)
device = /dev/ttyUSB%m1
baudrate = 115200

Activate the configuration profile by pattern match:

$ tio usb12

Which becomes equivalent to:

$ tio -b 115200 /dev/ttyUSB12

It is also possible to combine use of configuration profile and command-line options. For example:

$ tio -l -t usb12

EXAMPLES

Typical use is without options:

$ tio /dev/ttyUSB0

Which corresponds to the commonly used default options:

$ tio -b 115200 -d 8 -f none -s 1 -p none /dev/ttyUSB0

It is recommended to connect serial TTY devices by ID:

$ tio /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0

Using serial devices by ID ensures that tio automatically reconnects to the correct serial device if it is disconnected and then reconnected.

Redirect serial device I/O to Unix file socket for scripting:

$ tio -S unix:/tmp/tio-socket0 /dev/ttyUSB0

Then, to issue a command via the file socket simply do:

$ echo "ls -la" | nc -UN /tmp/tio-socket0 > /dev/null

Or use the expect command to script an interaction:

#!/usr/bin/expect -f

set timeout -1
log_user 0

spawn nc -UN /tmp/tio-socket0
set uart $spawn_id

send -i $uart "date\n"
expect -i $uart "prompt> "
send -i $uart "ls -la\n"
expect -i $uart "prompt> "

It is also possible to use tio's own simpler expect/send script functionality to e.g. automate logins:

$ tio --script 'expect("login: "); write("root\n"); expect("Password: "); write("root\n")' /dev/ttyUSB0

Redirect device I/O to network file socket for remote TTY sharing:

$ tio --socket inet:4444 /dev/ttyUSB0

Then, use netcat to connect to the shared TTY session over network (assuming tio is hosted on IP 10.0.0.42):

$ nc -N 10.0.0.42 4444

Pipe command to the serial device:

$ echo "ls -la" | tio /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0

Pipe command to serial device and wait for line response within 1 second:

$ echo "*IDN?" | tio /dev/ttyACM0 --script "expect('\r\n', 1000)" --mute

Likewise, to pipe data from file to the serial device:

$ cat data.bin | tio /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0

Map NL to CR-NL on input from device and DEL to BS on output to device:

$ tio --map INLCRNL,ODELBS /dev/ttyUSB0

Enable RS-485 mode:

$ tio --rs-485 --rs-485-config=RTS_ON_SEND=1,RX_DURING_TX /dev/ttyUSB0

Manipulate DTR and RTS lines upon first connect to reset connected microcontroller:

$ tio --script "set{DTR=high,RTS=low}; msleep(100); set{RTS=toggle}" --script-run once /dev/ttyUSB0

WEBSITE

Visit https://tio.github.io

AUTHOR

Maintained by Martin Lund <martin.lund@keep-it-simple.com>.