Ultimate Index API

-- Set local variables
-- This is an internal function called by updateIndex to initalize the search index.
function updateIndexFile(path)
    indexedFiles[path] = ""
    local file = fs.open(path, "r")
    if file then
        local line = file.readAll()
        file.close()
        indexedFiles[path] = line
    else
        indexedFiles[path] = ""
    end
end

-- This is an internal function called by rebuildIndex to initalize the search index.
-- It loops through the directory list and calls itself if it finds a directory.
function updateIndex(path)
    if fs.isDir(path) then
        for k, v in pairs(fs.list(path)) do
            if fs.isDir(path.."/"..v) then
                updateIndex(path.."/"..v)
            else
                updateIndexFile(path.."/"..v)
            end
        end
    elseif fs.exists(path) then
        updateIndexFile(path)
    end
end

-- This is an internal function run by Lua Script System to initalize the search index.
-- It is run on startup to initalize the index. If you are not using LuaSS then you need to run this before the
-- first time you search files using the searchFiles or searchFileName functions given by this API.
-- Currently it just calls updateIndex to index the root directory.
function rebuildIndex()
    updateIndex("")
end

-- This is an internal function used to check if a file should be included in the table returned by searchFiles.
function findStringInIndexSearchFiles(path, sSearch)
    local contents = indexedFiles[path]
    local startHere = 0
    while true do
        local nextSlash = string.find(string.sub(contents, startHere, -1), sSearch)
        if not nextSlash then
            return
        else
            fileContentIndex[sSearch][#fileContentIndex[sSearch] + 1] = path
            return true
        end
        nextSlash = nextSlash + startHere
        tab = tab + 1
        startHere = nextSlash
    end
end

-- This is an internal function used to check if a file should be included in the table returned by searchFileNames.
function findStringInIndexSearchFileNames(path, sSearch)
    local match = string.find(path, sSearch)
    if match then
        fileNameIndex[sSearch][#fileNameIndex[sSearch] + 1] = path
        return true
    end
end

function checkIfIndexed()
    if not indexedFiles then
        indexedFiles = {} -- This table is used to store indexed file contents.
        fileContentIndex = {} -- This table is used to store file content matches.
        fileNameIndex = {} -- This table is used to store file name matches.
        print("Indexing Files...")
        rebuildIndex()
    end
end

-- This function searches inside files for the searchstring sSearch.
function searchFiles(sSearch)
    checkIfIndexed()
    local tab = fileContentIndex[sSearch]
    if tab then
        return tab
    else
        fileContentIndex[sSearch] = {}
        for k, v in pairs(indexedFiles) do
            findStringInIndexSearchFiles(k, sSearch)
        end
        return fileContentIndex[sSearch]
    end
end

-- This function searches for files with names that include the string sSearch.
function searchFileNames(sSearch)
    checkIfIndexed()
    local tab = fileNameIndex[sSearch]
    if tab then
        return tab
    else
        fileNameIndex[sSearch] = {}
        for k, v in pairs(indexedFiles) do
            findStringInIndexSearchFileNames(k, sSearch)
        end
        return fileNameIndex[sSearch]
    end
end

local function printUsage()
    if shell then
        print("To search files, use "..shell.getRunningProgram().." search <name>.")
        print("To search file names, use "..shell.getRunningProgram().." find <name>.")
        print("To rebuild the index, use "..shell.getRunningProgram().." rebuild.")
    end
end

local tArgs = {...}
if #tArgs > 0 then
    if #tArgs > 1 then
        if tArgs[1] == "find" then
            textutils.pagedTabulate(searchFileNames(tArgs[2]))
        elseif tArgs[1] == "search" then
            textutils.pagedTabulate(searchFiles(tArgs[2]))
        else
            printUsage()
        end
    elseif tArgs[1] == "rebuild" then
        rebuildIndex()
    else
        printUsage()
    end
else
    if shell then
        checkIfIndexed()
        printUsage()
    end
end