History persistence for OpenOS

README.md

History persistence for OpenOS

Installation

1. Add the path to historysvc.lua to .shrc
2. Copy history.lua to a directory in $PATH

history.lua

local args = {...}
local shell = require("shell")
local HISTORY_FILE = (os.getenv("HOME") or "/home") .. "/.history"

local function load_history()
    local history = {}
    local fs = require("filesystem")

    if fs.exists(HISTORY_FILE) then
        local file = io.open(HISTORY_FILE, "r")

        if file then
            for line in file:lines() do
                line = line:match("^%s*(.-)%s*$")

                if #line > 0 then
                    table.insert(history, line)
                end
            end

            file:close()
        end
    end

    return history
end

local history = load_history()

if #args == 0 then
    if #history == 0 then
        print("No history available.")
    else
        for i = 1, #history do
            print(string.format("%4d  %s", i, history[i]))
        end
    end
elseif args[1] == "-c" then
    local file = io.open(HISTORY_FILE, "w")

    if file then
        file:close()
        print("History cleared.")
    end
elseif args[1] == "-q" then
    print("Stopping history service...")
    local computer = require("computer")
    computer.pushSignal("history_service_stop")
    print("History service stop signal sent.")
elseif args[1] == "-h" or args[1] == "--help" then
    print("Usage: history [-c|-q|-h] [number]")
    print("  (no args)  Show entire history with numbers")
    print("  -c         Clear history")
    print("  -q         Stop history service")
    print("  -h         Show this help message")
    print("  number     Execute command with that history number")
elseif tonumber(args[1]) then
    local num = tonumber(args[1])

    if num > 0 and num <= #history then
        local command = history[num]
        print("Executing: " .. command)
        shell.execute(command)
    else
        print("Error: History entry " .. num .. " does not exist.")
        print("Available history entries: 1-" .. #history)
    end
else
    print("Error: Invalid argument '" .. args[1] .. "'")
    print("Use 'history -h' for usage information.")
end

historysvc.lua

local fs = require("filesystem")
local event = require("event")
local sh = require("sh")

local HISTORY_FILE = (os.getenv("HOME") or "/home") .. "/.history"
local MAX_HISTORY = tonumber(os.getenv("HISTSIZE")) or 100

local history = {}
local service_running = false

local function load_history()
    history = {}

    if fs.exists(HISTORY_FILE) then
        local file = io.open(HISTORY_FILE, "r")

        if file then
            for line in file:lines() do
                line = line:match("^%s*(.-)%s*$")

                if #line > 0 then
                    table.insert(history, line)
                end
            end

            file:close()
        end
    end
end

local function save_command(command)
    command = command:match("^%s*(.-)%s*$")

    if #command == 0 or (#history > 0 and history[#history] == command) then
        return
    end

    if command:match("^history%s") or command == "history" then
        return
    end

    table.insert(history, command)

    if #history > MAX_HISTORY then
        table.remove(history, 1)
        local file = io.open(HISTORY_FILE, "w")

        if file then
            for _, cmd in ipairs(history) do
                file:write(cmd, "\n")
            end

            file:close()
        end
    else
        local file = io.open(HISTORY_FILE, "a")

        if file then
            file:write(command, "\n")
            file:close()
        end
    end
end

local function hook_shell_input()
    local tty = require("tty")

    local original_window = tty.window
    local window_proxy = setmetatable({}, {
        __index = original_window,
        __newindex = function(_, key, value)
            if key == "cursor" and value and type(value) == "table" then
                for i = #history, math.max(1, #history - MAX_HISTORY + 1), -1 do
                    local idx = #history - i + 1

                    if idx <= MAX_HISTORY then
                        value[idx] = history[i]
                    end
                end

                if not value.hint then
                    value.hint = sh.hintHandler
                end
            end
            original_window[key] = value
        end
    })

    tty.window = window_proxy
    local core_cursor = require("core/cursor")

    if core_cursor.read then
        local original_cursor_read = core_cursor.read

        core_cursor.read = function(cursor)
            local result = original_cursor_read(cursor)

            if result and type(result) == "string" then
                local trimmed = result:match("^%s*(.-)%s*$")

                if #trimmed > 0 and trimmed ~= "" then
                    pcall(save_command, trimmed)
                end
            end

            return result
        end
    end
end

local function initialize()
    if service_running then
        return
    end

    print("Loading shell history service...")

    load_history()
    print("Loaded " .. #history .. " commands from history")

    hook_shell_input()
    service_running = true

    print("Shell history service started.")
    print("Commands will be logged to " .. HISTORY_FILE)
    print("Use 'history' command to view saved commands, 'history N' to execute command N.")
end

local function cleanup()
    if not service_running then
        return
    end

    service_running = false
    print("Shell history service stopped.")
end

local function on_service_stop()
    cleanup()
    print("History service stopped by user request.")
    os.exit()
end

event.listen("history_service_stop", on_service_stop)
initialize()

print("History service initialization complete.")