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.
To make a simpler serial device tool for working with serial TTY devices with less focus on classic terminal/modem features and more focus on the needs of embedded developers and hackers.
tio was originally created as an alternative to screen for connecting to serial devices when used in combination with tmux.
- Easily connect to serial TTY devices
- Sensible defaults (115200 8n1)
- Automatic connection management
- Automatic detection of serial ports
- Automatic reconnect
- Automatically connect to first new appearing serial device
- Automatically connect to latest registered serial device
- Connect to same port/device combination via unique topology ID (TID)
- Useful for reconnecting when serial device has no serial device by ID
- Support for non-standard baud rates
- Support for mark and space parity
- X-modem (1K/CRC) and Y-modem file upload
- Support for RS-485 mode
- List available serial devices
- By device
- Including topology ID, uptime, driver, description
- Sorted by uptime (newest device listed last)
- By ID
- By path
- By device
- Show RX/TX statistics
- Toggle serial lines
- Pulse serial lines with configurable pulse duration
- Local echo support
- Remapping of characters (nl, cr-nl, bs, lowercase to uppercase, etc.)
- Switchable independent input and output
- Normal mode
- Hex mode (output supports variable width)
- Line mode (input only)
- Timestamp support
- Per line in normal output mode
- Output timeout timestamps in hex output mode
- Support for delayed output
- Per character
- Per line
- Log to file
- Automatic naming of log file (default)
- Configurable directory for saving automatic named log files
- Manual naming of log file
- Overwrite (default) or append to log file
- Strip control characters and escape sequences
- Configuration file support
- Support for configuration profiles
- Activate configuration profiles by name or pattern
- Support for including other configuration files
- Redirect I/O of shell command to serial device
- Redirect I/O to UNIX socket or IPv4/v6 network socket
- Useful for scripting or TTY sharing
- Pipe input and/or output
- Bash completion on options, serial device names, and profile names
- Configurable tio message text color
- Supports NO_COLOR env variable as per no-color.org
- Visual or audible alert on connect/disconnect
- Remapping of prefix key
- Lua scripting support for automation
- Run script manually or automatically at connect (once/always/never)
- Simple expect/send like functionality with support for regular expressions
- Manipulate port modem lines (useful for microcontroller reset/boot etc.)
- Send files via x/y-modem protocol
- Search for serial devices
- Man page documentation
- Plays nicely with tmux and similar terminal multiplexers
For more usage details please see the man page documentation here.
The command-line interface is straightforward as reflected in the output from
tio --help:
Usage: tio [<options>] <tty-device|profile|tid>
Connect to TTY device directly or via configuration profile or topology ID.
Options:
-b, --baudrate <bps> Baud rate (default: 115200)
-d, --databits 5|6|7|8 Data bits (default: 8)
-f, --flow hard|soft|none Flow control (default: none)
-s, --stopbits 1|2 Stop bits (default: 1)
-p, --parity odd|even|none|mark|space Parity (default: none)
-o, --output-delay <ms> Output character delay (default: 0)
-O, --output-line-delay <ms> Output line delay (default: 0)
--line-pulse-duration <duration> Set line pulse duration
-a, --auto-connect new|latest|direct Automatic connect strategy (default: direct)
--exclude-devices <pattern> Exclude devices by pattern
--exclude-drivers <pattern> Exclude drivers by pattern
--exclude-tids <pattern> Exclude topology IDs by pattern
-n, --no-reconnect Do not reconnect
-e, --local-echo Enable local echo
--input-mode normal|hex|line Select input mode (default: normal)
--output-mode normal|hex|hexN Select output mode (default: normal)
-t, --timestamp Enable line timestamp
--timestamp-format <format> Set timestamp format (default: 24hour)
--timestamp-timeout <ms> Set timestamp timeout (default: 200)
-l, --list List available serial devices, TIDs, and profiles
-L, --log Enable log to file
--log-file <filename> Set log filename
--log-directory <path> Set log directory path for automatic named logs
--log-append Append to log file
--log-strip Strip control characters and escape sequences
-m, --map <flags> Map characters
-c, --color 0..255|bold|none|list Colorize tio text (default: bold)
-S, --socket <socket> Redirect I/O to socket
--rs-485 Enable RS-485 mode
--rs-485-config <config> Set RS-485 configuration
--alert bell|blink|none Alert on connect/disconnect (default: none)
--mute Mute tio messages
--script <string> Run script from string
--script-file <filename> Run script from file
--script-run once|always|never Run script on connect (default: always)
--exec <command> Execute shell command with I/O redirected to device
-v, --version Display version
-h, --help Display help
Options and profiles may be set via configuration file.
In session you can press ctrl-t ? to list available key commands.
See the man page for more details.
By default tio automatically connects to the provided TTY device. If the device
is not present, tio will wait for it to appear and then connect. If the
connection is lost (e.g. device is unplugged), it will wait for the device to
reappear and then reconnect. However, if the --no-reconnect option is
provided, tio will exit if the device is not present or an established
connection is lost.
Typical use is without options:
$ tio /dev/ttyUSB0
Which corresponds to the commonly used default options:
$ tio --baudrate 115200 --databits 8 --flow none --stopbits 1 --parity none /dev/ttyUSB0
List available serial devices:
$ tio --list
Device TID Uptime [s] Driver Description
----------------- ---- ------------- ---------------- --------------------------
/dev/ttyS4 BaaB 19526.576 port 16550A UART
/dev/ttyS5 eV0Z 19525.845 port 16550A UART
/dev/ttyUSB1 bCC2 1023.274 ftdi_sio TTL232R-3V3
/dev/ttyUSB0 SPpw 978.527 ftdi_sio TTL232RG-VREG3V3
/dev/ttyACM0 i5q4 2.079 cdc_acm ST-Link VCP Ctrl
By-id
--------------------------------------------------------------------------------
/dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTCHUV56-if00-port0
/dev/serial/by-id/usb-FTDI_TTL232RG-VREG3V3_FT1NELUB-if00-port0
/dev/serial/by-id/usb-STMicroelectronics_STLINK-V3_004900343438510234313939-if02
By-path
--------------------------------------------------------------------------------
/dev/serial/by-path/pci-0000:00:14.0-usb-0:8.1.3.1.4:1.0-port0
/dev/serial/by-path/pci-0000:00:14.0-usbv2-0:8.1.3.1.4:1.0-port0
/dev/serial/by-path/pci-0000:00:14.0-usbv2-0:6.4:1.0-port0
/dev/serial/by-path/pci-0000:00:14.0-usb-0:6.4:1.0-port0
/dev/serial/by-path/pci-0000:00:14.0-usbv2-0:6.3:1.2
/dev/serial/by-path/pci-0000:00:14.0-usb-0:6.3:1.2
Configuration profiles (/home/lundmar/.config/tio/config)
--------------------------------------------------------------------------------
rpi3 stm32 esp32 am64-evm
imx8mp-evk nucleo-h743zi2 usb-devices
It is recommended to connect serial TTY devices by ID:
$ tio /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTCHUV56-if00-port0
Note: Using serial devices by ID helps ensure that tio automatically reconnects to the same serial device when reattached, even when it enumerates differently.
If no serial device by ID is available it is recommended to connect via topology ID (TID):
$ tio bCC2
Note: The TID is unique and will stay the same as long as your USB serial port device plugs into the same USB topology (same ports, same hubs, same connections, etc.). This way it is possible for tio to successfully reconnect to the same device.
Connect automatically to first new appearing serial device:
$ tio --auto-connect new
Connect automatically to latest registered serial device:
$ tio --auto-connect latest
It is possible to use exclude options to affect which serial devices are involved in the automatic connection strategy:
$ tio --auto-connect new --exclude-devices "/dev/ttyACM?,/dev/ttyUSB2"
And to exclude drivers by pattern:
$ tio --auto-connect new --exclude-drivers "cdc_acm,ftdi_sio"
Note: Pattern matching supports '*' and '?'. Use comma separation to define multiple patterns.
To include drivers by specific pattern simply negate the exclude option:
$ tio --auto-connect new --exclude-drivers !("cp2102")
Log to file with autogenerated filename:
$ tio --log /dev/ttyUSB0
Log to file with specific filename:
$ tio --log --log-file my-log.txt
Enable ISO8601 timestamps per line:
$ tio --timestamp --timestamp-format iso8601 /dev/ttyUSB0
Output to hex with width 16:
$ tio --output-mode hex16 /dev/ttyUSB0
Redirect I/O to IPv4 network socket on port 4242:
$ tio --socket inet:4242 /dev/ttyUSB0
Pipe data to the serial device:
$ cat data.bin | tio /dev/ttyUSB0
Manipulate modem lines on connect:
$ tio --script "set{DTR=high,RTS=low}; msleep(100); set{DTR=toggle,RTS=toggle}" /dev/ttyUSB0
Pipe command to serial device and wait for line response within 1 second:
$ echo "*IDN?" | tio /dev/ttyACM0 --script "expect('\r\n', 1000)" --mute
KORAD KD3305P V4.2 SN:32475045
Various in session key commands are supported. When tio is started, press ctrl-t ? to list the available key commands.
[15:02:53.269] Key commands:
[15:02:53.269] ctrl-t ? List available key commands
[15:02:53.269] ctrl-t b Send break
[15:02:53.269] ctrl-t c Show configuration
[15:02:53.269] ctrl-t e Toggle local echo mode
[15:02:53.269] ctrl-t f Toggle log to file
[15:02:53.269] ctrl-t F Flush data I/O buffers
[15:02:53.269] ctrl-t g Toggle serial port line
[15:02:53.269] ctrl-t i Toggle input mode
[15:02:53.269] ctrl-t l Clear screen
[15:02:53.269] ctrl-t L Show line states
[15:02:53.269] ctrl-t m Change mapping of characters on input or output
[15:02:53.269] ctrl-t o Toggle output mode
[15:02:53.269] ctrl-t p Pulse serial port line
[15:02:53.269] ctrl-t q Quit
[15:02:53.269] ctrl-t r Run script
[15:02:53.269] ctrl-t R Execute shell command with I/O redirected to device
[15:02:53.269] ctrl-t s Show statistics
[15:02:53.269] ctrl-t t Toggle line timestamp mode
[15:02:53.269] ctrl-t v Show version
[15:02:53.269] ctrl-t x Send file via Xmodem
[15:02:53.269] ctrl-t y Send file via Ymodem
[15:02:53.269] ctrl-t ctrl-t Send ctrl-t character
If needed, the prefix key (ctrl-t) can be remapped via configuration file.
Options can be set via the configuration file first found in any of the following locations in the order listed:
- $XDG_CONFIG_HOME/tio/config
- $HOME/.config/tio/config
- $HOME/.tioconfig
The configuration file supports profiles using named sections which can be activated via the command-line by name or pattern. A profile specifies which TTY device to connect to and other options.
Example configuration file:
[default]
baudrate = 115200
databits = 8
parity = none
stopbits = 1
color = 10
[rpi3]
device = /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0
no-reconnect = true
log = true
log-file = rpi3.log
line-pulse-duration = DTR=200,RTS=150
color = 11
[svf2]
device = /dev/ttyUSB0
baudrate = 9600
script = expect("login: "); write("root\n"); expect("Password: "); write("root\n")
color = 12
[esp32]
device = /dev/serial/by-id/usb-0403_6014-if00-port0
script = set{DTR=high,RTS=low}; msleep(100); set{DTR=low,RTS=high}; msleep(100); set{RTS=low}
script-run = once
color = 13
[usb-devices]
pattern = ^usb([0-9]*)
device = /dev/ttyUSB%m1
color = 14
To use a specific profile by name simply start tio like so:
$ tio rpi3
Or by pattern match:
$ tio usb12
Another more elaborate configuration file example is available here.
Tio suppots Lua scripting to easily automate interaction with the tty device.
In addition to the Lua API tio makes the following functions available:
expect(string, timeout)
Expect string - waits for string to match or timeout before continueing.
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.
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 miliseconds.
exit(code)
Exit with exit code.
Packages for various GNU/Linux distributions are available. Please consult your package manager tool to find and install tio.
If you would like to see tio included in your favorite distribution, please reach out to its package maintainers team.
Install latest stable version:
$ snap install tio --classic
Note: Classic confinement is currently required due to limitations of the snapcraft framework. See Issue #187 for discussion.
If you have brew installed:
$ brew install tio
If you have MSYS2 installed:
$ pacman -S tio
The latest source releases can be found here.
Before running the install steps make sure you have glib and lua libraries installed. For example:
$ sudo apt install libglib2.0-dev liblua5.2-dev
Install steps:
$ meson setup build
$ meson compile -C build
$ meson install -C build
See meson_options.txt for tio specific build options.
Note: The meson install steps may differ depending on your specific system.
Getting permission access errors trying to open your serial device?
Add your user to the group which allows serial device access permanently. For example, to add your user to the 'dialout' group do:
sudo usermod -a -G dialout <username>Switch to the "dialout" group, temporary but immediately for this session.
newgrp dialoutThis is an open source project - all contributions (bug reports, code, doc, ideas, etc.) are welcome.
Please use the github issue tracker and pull request features.
Also, if you find this free open source software useful please feel free to consider making a donation of your choice:
Submit bug reports via GitHub: https://github.com/tio/tio/issues
Visit tio.github.io
tio is GPLv2+. See LICENSE file for more details.
Maintained by Martin Lund <martin.lund@keep-it-simple.com>
See the AUTHORS file for full list of contributors.