# tio - a simple serial device I/O tool

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## 1. Introduction

tio is a simple 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.

<p align="center">
<img src="images/tio-demo.gif">
</p>

### 1.1 Motivation

To make a simpler serial device tool for talking 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 to replace
[screen](https://www.gnu.org/software/screen) for connecting to serial devices
when used in combination with [tmux](https://tmux.github.io).

## 2. Features

 * Easily connect to serial TTY devices
 * Automatic connect and reconnect
 * Support for arbitrary baud rates
 * List available serial devices by ID
 * Show RX/TX statistics
 * Toggle serial lines
 * Pulse serial lines with configurable pulse duration
 * Local echo support
 * Map characters (nl, cr-nl, bs, lowercase to uppercase, etc.)
 * Line timestamps
 * Support for delayed output per character
 * Support for delayed output per line
 * Hexadecimal mode
 * Log to file
 * Autogeneration of log filename
 * Configuration file support
 * Activate sub-configurations by name or pattern
 * Redirect I/O to file or network socket for scripting or TTY sharing
 * Pipe input and/or output
 * Bash completion
 * Color support
 * Remapping of prefix key
 * Man page documentation

## 3. Usage

For more usage details please see the man page documentation
[here](man/tio.1.txt).

### 3.1 Command-line

The command-line interface is straightforward as reflected in the output from
'tio --help':
```
  Usage: tio [<options>] <tty-device|sub-config>

  Connect to tty device directly or via sub-configuration.

  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
    -n, --no-autoconnect                   Disable automatic connect
    -e, --local-echo                       Enable local echo
    -t, --timestamp                        Enable line timestamp
        --timestamp-format <format>        Set timestamp format (default: 24hour)
    -L, --list-devices                     List available serial devices
    -l, --log                              Enable log to file
        --log-file <filename>              Set log filename
        --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 file or network socket
    -x, --hexadecimal                      Enable hexadecimal mode
    -v, --version                          Display version
    -h, --help                             Display help

  Options and sub-configurations may be set via configuration file.

  See the man page for more details.

```

By default tio automatically connects to the provided TTY device if present.
If the device is not present, it will wait for it to appear and then connect.
If the connection is lost (eg. device is unplugged), it will wait for the
device to reappear and then reconnect. However, if the `--no-autoconnect`
option is provided, tio will exit if the device is not present or an
established connection is lost.

tio features full bash autocompletion.


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.

### 3.2 Key commands

Various in session key commands are supported. When tio is started, press
ctrl-t ? to list the available key commands.

```
[20:19:12.040] Key commands:
[20:19:12.040]  ctrl-t ?   List available key commands
[20:19:12.040]  ctrl-t b   Send break
[20:19:12.040]  ctrl-t c   Show configuration
[20:19:12.040]  ctrl-t e   Toggle local echo mode
[20:19:12.040]  ctrl-t g   Toggle serial port line
[20:19:12.040]  ctrl-t h   Toggle hexadecimal mode
[20:19:12.040]  ctrl-t l   Clear screen
[20:19:12.040]  ctrl-t L   Show line states
[20:19:12.040]  ctrl-t p   Pulse serial port line
[20:19:12.040]  ctrl-t q   Quit
[20:19:12.041]  ctrl-t s   Show statistics
[20:19:12.041]  ctrl-t T   Toggle line timestamp mode
[20:19:12.041]  ctrl-t U   Toggle conversion to uppercase
[20:19:12.041]  ctrl-t v   Show version
```

If needed, the prefix key (ctrl-t) can be remapped via configuration file.

### 3.3 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/tiorc
 - $HOME/.config/tio/tiorc
 - $HOME/.tiorc

The configuration file supports sub-configurations using named sections which can
be activated via the command-line by name or pattern. A sub-configuration
specifies which tty to connect to and other options.

Example configuration file:

```
# Defaults
baudrate = 9600
databits = 8
parity = none
stopbits = 1
color = 10

[rpi3]
tty = /dev/serial/by-id/usb-FTDI_TTL232R-3V3_FTGQVXBL-if00-port0
baudrate = 115200
no-autoconnect = enable
log = enable
log-file = rpi3.log
line-pulse-duration = DTR=200,RTS=150
color = 12

[usb devices]
pattern = usb([0-9]*)
tty = /dev/ttyUSB%s
color = 13
```

To use a specific sub-configuration by name simply start tio like so:
```
$ tio rpi3
```
Or by pattern match:
```
$ tio usb12
```

Another configuration file example is available [here](example/tiorc).

## 4. Installation

### 4.1 Installation using package manager (Linux)

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 their package maintainers team.

### 4.2 Installation using snap (Linux)

Install latest stable version:
```
    $ snap install tio
```

### 4.3 Installation using brew (MacOS, Linux)

If you have [brew](http://brew.sh) installed:
```
    $ brew install tio
```

### 4.4 Installation using MacPorts (MacOS)

If you have [MacPorts](https://www.macports.org) installed:
```
    $ sudo port install tio
```

### 4.5 Installation from source

The latest source releases can be found [here](https://github.com/tio/tio/releases).

Install steps:
```
    $ meson build
    $ meson compile -C build
    $ meson install -C build
```

See meson\_options.txt for tio specific build options.

Note: It is recommended to only try to install from source if you are familiar
with how to build stuff using meson.


## 5. Contributing

tio is open source. If you want to help out with the project please feel free
to join in.

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:

[![Donate](images/paypal.png)](https://www.paypal.me/lundmar)


## 6. Support

Submit bug reports via GitHub: https://github.com/tio/tio/issues


## 7. Website

Visit [tio.github.io](https://tio.github.io)


## 8. License

tio is GPLv2+. See LICENSE file for more details.


## 9. Authors

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

See the AUTHORS file for full list of contributors.
