pty key remapper

1_ptyremap.py

#!/usr/bin/env python
import argparse
import os
import pty
import signal
import sys
import termios


parser = argparse.ArgumentParser()
parser.add_argument("filename", nargs="?")
options = parser.parse_args()

shell = os.environ.get("SHELL", "sh")
filename = options.filename


def parseconfig(path):
    root = [None] * 257
    if path is None:
        # return root
        path = os.path.dirname(__file__) + "/config.py"

    env = {}
    exec(open(path).read(), env)

    for k, v in env["config"].items():
        buf = k.encode()
        node = root
        for b in buf:
            if node[b] is None:
                node[b] = [None] * 257
            node = node[b]
        node[256] = v.encode()
    return root


def find(trie, buf, start):
    for i in range(start, len(buf)):
        c = buf[i]
        suc = trie[c]
        if suc is None:
            return (i + 1, None)
        result = suc[256]
        if result is not None:
            return (i + 1, result)
        trie = suc
    return None


trie = parseconfig(filename)

size = None

mfd = None


def resize(*unused):
    if mfd is not None:
        newsize = termios.tcgetwinsize(sys.stdin.fileno())
        termios.tcsetwinsize(mfd, newsize)
    pass


signal.signal(signal.SIGWINCH, resize)


def read1(fd):
    global mfd
    if mfd is None:
        mfd = fd
        resize()
    data = os.read(fd, 1048576)
    return data


logfile = open("/tmp/ptylog", "wb")


def log(msg):
    logfile.write("key:".encode())
    logfile.write(msg)
    logfile.write("\n".encode())
    logfile.flush()


def read2(fd):
    global trie
    result = b""
    buf = os.read(fd, 1048576)
    log(buf)
    if buf[0] == 0x1B:
        return buf
    while True:
        found = find(trie, buf, 0)
        if found is None:
            # ここ(マッピングが解決できないタイミング)以外でreadすると詰まる
            buf = buf + os.read(fd, 1048576)
            log(buf)
            continue
        if found[1] is None:
            result += buf[0 : found[0]]
        else:
            if found[1] == b"reload":
                trie = parseconfig(filename)
                pass
            result += found[1]
        buf = buf[found[0] :]
        if len(buf) == 0:
            break
    return result


pty.spawn(shell, read1, read2)

config.py

config = {}

a = "abcdefghijklmnopqrstuvwxyz"
j = "かきくさしすたちつなにぬはひふまみむめやいゆらりるれ"
for i in range(len(a)):
    config[j[i]] = a[i]
    config["あ" + j[i]] = a[i].upper()
    config["う" + j[i]] = chr(ord(a[i]) - 0x60)
    config["え" + j[i]] = "\x1b" + a[i]

# わ + あ行は数値シフトの記号
j = "あかさたなはまやらわ"
a = "!@#$%^&*()"

for i in range(len(a)):
    config["わ" + j[i]] = a[i]

# Vimだとドットの使用率の方が高いので入れ替える
config["、"] = "."
config["。"] = ","

config["を"] = ";"
config["ん"] = "'"
config["ー"] = "/"

config['ア'] = 'reload'