NAME

	ktrans – language transliterator

SYNOPSIS

	ktrans [ –G ] [ –l lang ] [ kbdtap ]

DESCRIPTION

Ktrans transliterates a stream of keyboard events. Without any arguments, ktrans reads events from standard input and writes out converted events to stdout. If a kbdtap file is given, it is used for both input and output instead. By default ktrans starts in passthrough mode, echoing out the input with no conversions. The initial language is set with the –l flag. After operation has begun, the language may be changed by either typing a control sequence and/or through the plumber. The following table provides the control sequence and lang strings accepted for each supported language respectfully. English (Passthrough). ctl–t and en Japanese Hiragana. ctl–n and jp Japanese Katakana. ctl–k and jpk Chinese. ctl–c and zh Korean. ctl–s and ko Vietnamese. ctl–v and vn Ktrans listens on the lang plumber port for switching languages. The data accepted on this port is the same as the –l flag's lang argument.

CONVERSION

Conversion is done in two layers, an implicit layer for unambiguous mappings, and an explicit layer for selecting one match out of a list of ambiguous matches. The following control characters are used for conversion instructions. ctl–\ Explicitly match the current input, consecutive inputs of ctl–\ will cycle through all the possible options. ctl–l Reset the current input buffer. The implicit layer happens automatically as characters are input, transforming a consecutive set of key strokes in to their rune counterpart. A series of runes may then be explicitly matched by cycling through a list of options. Ktrans automatically maintains a buffer of the current series of key strokes being considered for an explicit match, and resets that buffer on logical "word" breaks depending on the language. However in some cases the automatic hinting will be insufficient. Input is always passed along, when a match is found Ktrans will emit backspaces to clear the input sequence and replace it with the matched sequence. Once ctl–\ has been used to start the selection of an explicit match, the up and down arrow keys may be used to thumb around the options.

DISPLAY

Ktrans will provide a graphical display of current explicit conversion candidates as implicit conversion is done. Candidates are highlighted as a user cycles through them. At the bottom of the list is an exit button for quitting the program. Keyboard input typed in to the window is transliterated but discarded, providing a scratch input space. The mouse may be used to scroll through and select candidates, but it requires that ktrans is started using rio(1)'s –k flag. The –G flag disables the graphical display entirely.

KEY MAPPING

For convenience, the control characters used by ktrans can be mapped directly to physical keys through modifications of the kbmap (see kbdfs(8)). The /sys/lib/kbmap/jp mapping will turn language input keys present on Japanese A01/106/109(A) in to control sequences matching their label: Henkan Convert to Kanji (ctl–\) Muhenkan Clear Kanji buffer (ctl–l) Hiragana / Katakana Switch to Hiragana (ctl–n) Shift + Hiragana / Katakana Switch to Katakana (ctl–k) Hankaku / Zenkaku Switch to Hiragana (ctl–n) Shift + Hankaku / Zenkaku Switch to passthrough (ctl–t) Shift + Space Convert to Kanji (ctl–\). This is a fallback for keyboards without a physical Henkan key.

DICTIONARIES

All implicit and explicit matching dictionaries are provided as plain text files within /lib/ktrans. The formats of which are specified within ktrans(6). Additionally, dictionaries located in $home/lib/ktrans/ will be merged on top of the system dictionaries. Merging is done at a list level only; Keys that appear replace all values of the previous definition. For backwards compatibility the jisho and zidian environment variables may also be set to pick alternate system dictionaries for Japanese and Chinese respectfully.

LANGUAGES

JAPANESE The Hiragana and Katakana modes implicitly turn Hepburn representations in to their Kana counterparts. Explicit conversions combine sequences of Hiragana in to Kanji. Capital Latin input is used for hinting. For adjectives and verbs, a single capital is used as an Okurigana hint. For example, 動かす is typed as 'ugoKasu[^\]'. The hint serves two purposes, it is provided as part of the explicit sequence for Kanji lookup and denotes that the following runes are Okurigana. For particles, the entire Kana may be input in upper case. This similarly denotes the end of the Kanji portion of the sequence, but is not used as part of the lookup sequence itself. So to write 私の猫 the user types "watashiNO[^\]neko[^\]". Note that in both cases we have successfully communicated to ktrans when to reset the explicit match buffer without needing to explicitly give a ctl–l character. CHINESE Implicit conversion converts punctuation. Explicit matches use a dictionary to convert a series of Latin characters into Hanzi. By default a Wubizixing input dictionary is used. Additionally a Pinyin input dictionary is provided. VIETNAMESE Implicit conversion is modeled after Telex, supporting standard diacritic suffixes. KOREAN Mapping is done by emulating a Dubeolsik layout, with each Latin character mapping to a single Jamo. Sequences of Jamo are automatically converted to Hangul syllables.

EXAMPLES

To type the following Japanese text: 私は毎日35分以上歩いて、 更に10分電車に乗って学校に通います。 健康の維持にも役だっていますが、 なかなかたのしいものです。 your keyboard typing stream should be: watashiHA[^\]mainichi[^\]35[^l]fun[^\]ijou[^\]aruIte,[^\] saraNI[^\]10[^l]fun[^\]denshaNI[^\]noTte[^\]gakkouNI[^\] kayoImasu.[\n]kenkouNO[^\]ijiNImo[^\]yakuDAtteimasuga,[^\] nakanakatanoshiImonodesu.[\n] where [^\] and [^l] indicate 'ctl–\' and 'ctl–l', respectively.

SOURCE

	/sys/src/cmd/ktrans

SEE ALSO

	ktrans(6), rio(4), kbdfs(8)

BUGS

	There is no hint from rio when the user moves the cursor, as such moving it is unlikely to result in what the user expects. Plan 9 lacks support for rendering combinational Unicode sequences, limiting the use of some code ranges.

HISTORY

	Ktrans was originally written by Kenji Okamoto in August of 2000 for the 2nd edition of Plan 9. It was imported in to 9front in July of 2022, with patches by several contributors. It was towed inside the environment during the 2022 9front hackathon.