refactor parallel code

openos/grep.lua

@@ -0,0 +1,323 @@
+--[[
+An adaptation of Wobbo's grep
+https://raw.githubusercontent.com/OpenPrograms/Wobbo-Programs/master/grep/grep.lua
+]]--
+
+-- POSIX grep for OpenComputers
+-- one difference is that this version uses Lua regex, not POSIX regex.
+
+local fs = require("openos.filesystem")
+local shell = require("openos.shell")
+local tty = require("openos.tty")
+local computer = require("openos.computer")
+
+-- Process the command line arguments
+
+local args, options = shell.parse(...)
+
+local gpu = tty.gpu()
+
+local function printUsage(ostream, msg)
+  local s = ostream or io.stdout
+  if msg then
+    s:write(msg,'\n')
+  end
+  s:write([[Usage: grep [OPTION]... PATTERN [FILE]...
+Example: grep -i "hello world" menu.lua main.lua
+for more information, run: man grep
+]])
+end
+
+local PATTERNS = {args[1]}
+local FILES = {select(2, table.unpack(args))}
+
+local LABEL_COLOR = 0xb000b0
+local LINE_NUM_COLOR = 0x00FF00
+local MATCH_COLOR = 0xFF0000
+local COLON_COLOR = 0x00FFFF
+
+local function pop(...)
+  local result
+  for _,key in ipairs({...}) do
+    result = options[key] or result
+    options[key] = nil
+  end
+  return result
+end
+
+-- Specify the variables for the options
+local plain = pop('F','fixed-strings')
+      plain = not pop('e','--lua-regexp') and plain
+local pattern_file = pop('file')
+local match_whole_word = pop('w','word-regexp')
+local match_whole_line = pop('x','line-regexp')
+local ignore_case = pop('i','ignore-case')
+local stdin_label = pop('label') or '(standard input)'
+local stderr = pop('s','no-messages') and {write=function()end} or io.stderr
+local invert_match = not not pop('v','invert-match')
+
+-- no version output, just help
+if pop('V','version','help') then
+  printUsage()
+  return 0
+end
+
+local max_matches = tonumber(pop('max-count')) or math.huge
+local print_line_num = pop('n','line-number')
+local search_recursively = pop('r','recursive')
+
+-- Table with patterns to check for
+if pattern_file then
+  local pattern_file_path = shell.resolve(pattern_file)
+  if not fs.exists(pattern_file_path) then
+    stderr:write('grep: ',pattern_file,': file not found')
+    return 2
+  end
+  table.insert(FILES, 1, PATTERNS[1])
+  PATTERNS = {}
+  for line in io.lines(pattern_file_path) do
+    PATTERNS[#PATTERNS+1] = line
+  end
+end
+
+if #PATTERNS == 0 then
+  printUsage(stderr)
+  return 2
+end
+
+if #FILES == 0 then
+  FILES = search_recursively and {'.'} or {'-'}
+end
+
+if not options.h and search_recursively then
+  options.H = true
+end
+
+if #FILES < 2 then
+  options.h = true
+end
+
+local f_only = pop('l','files-with-matches')
+local no_only = pop('L','files-without-match') and not f_only
+
+local include_filename = pop('H','with-filename')
+  include_filename = not pop('h','no-filename') or include_filename
+
+local m_only = pop('o','only-matching')
+local quiet = pop('q','quiet','silent')
+
+local print_count = pop('c','count')
+local colorize = pop('color','colour') and io.output().tty and tty.isAvailable()
+
+local noop = function(...)return ...;end
+local setc = colorize and gpu.setForeground or noop
+local getc = colorize and gpu.getForeground or noop
+
+local trim = pop('t','trim')
+local trim_front = trim and function(s)return s:gsub('^%s+','')end or noop
+local trim_back  = trim and function(s)return s:gsub('%s+$','')end or noop
+
+if next(options) then
+  if not quiet then
+    printUsage(stderr, 'unexpected option: '..next(options))
+    return 2
+  end
+  return 0
+end
+-- Resolve the location of a file, without searching the path
+local function resolve(file)
+  if file:sub(1,1) == '/' then
+    return fs.canonical(file)
+  else
+    if file:sub(1,2) == './' then
+      file = file:sub(3, -1)
+    end
+    return fs.canonical(fs.concat(shell.getWorkingDirectory(), file))
+  end
+end
+
+--- Builds a case insensitive patterns, code from stackoverflow
+--- (questions/11401890/case-insensitive-lua-pattern-matching)
+if ignore_case then
+  for i=1,#PATTERNS do
+    -- find an optional '%' (group 1) followed by any character (group 2)
+    PATTERNS[i] = PATTERNS[i]:gsub("(%%?)(.)", function(percent, letter)
+      if percent ~= "" or not letter:match("%a") then
+        -- if the '%' matched, or `letter` is not a letter, return "as is"
+        return percent .. letter
+      else -- case-insensitive
+        return string.format("[%s%s]", letter:lower(), letter:upper())
+      end
+    end)
+  end
+end
+
+local function getAllFiles(dir, file_list)
+  for node in fs.list(shell.resolve(dir)) do
+    local rel_path = dir:gsub("/+$","") .. '/' .. node
+    local resolved_path = shell.resolve(rel_path)
+    if fs.isDirectory(resolved_path) then
+      getAllFiles(rel_path, file_list)
+    else
+      file_list[#file_list+1] = rel_path
+    end
+  end
+end
+
+if search_recursively then
+  local files = {}
+  for _,arg in ipairs(FILES) do
+    if fs.isDirectory(arg) then
+      getAllFiles(arg, files)
+    else
+      files[#files+1]=arg
+    end
+  end
+  FILES=files
+end
+
+-- Prepare an iterator for reading files
+local function readLines()
+  local curHand = nil
+  local curFile = nil
+  local meta = nil
+  return function()
+    if not curFile then
+      local file = table.remove(FILES, 1)
+      if not file then
+        return
+      end
+      meta = {line_num=0,hits=0}
+      if file == "-" then
+        curFile = file
+        meta.label = stdin_label
+        curHand = io.input()
+      else
+        meta.label = file
+        local file, reason = resolve(file)
+        if fs.exists(file) then
+          curHand, reason = io.open(file, 'r')
+          if not curHand then
+            local msg = string.format("failed to read from %s: %s", meta.label, reason)
+            stderr:write("grep: ",msg,"\n")
+            return false, 2
+          else
+            curFile = meta.label
+          end
+        else
+          stderr:write("grep: ",file,": file not found\n")
+          return false, 2
+        end
+      end
+    end
+    meta.line = nil
+    if not meta.close and curHand then
+      meta.line_num = meta.line_num + 1
+      meta.line = curHand:read("*l")
+    end
+    if not meta.line then
+      curFile = nil
+      if curHand then
+        curHand:close()
+      end
+      return false, meta
+    else
+      return meta, curFile
+    end
+  end
+end
+
+local function write(part, color)
+  local prev_color = color and getc()
+  if color then setc(color) end
+  io.write(part)
+  if color then setc(prev_color) end
+end
+local flush=(f_only or no_only or print_count) and function(m)
+  if no_only and m.hits == 0 or f_only and m.hits ~= 0 then
+    write(m.label, LABEL_COLOR)
+    write('\n')
+  elseif print_count then
+    if include_filename then
+      write(m.label, LABEL_COLOR)
+      write(':', COLON_COLOR)
+    end
+    write(m.hits)
+    write('\n')
+  end
+end
+local ec = nil
+local any_hit_ec = 1
+local function test(m,p)
+  local empty_line = true
+  local last_index, slen = 1, #m.line
+  local needs_filename, needs_line_num = include_filename, print_line_num
+  local hit_value = 1
+  while last_index <= slen and not m.close do
+    local i, j = m.line:find(p, last_index, plain)
+    local word_fail, line_fail =
+      match_whole_word and not (i and not (m.line:sub(i-1,i-1)..m.line:sub(j+1,j+1)):find("[%a_]")),
+      match_whole_line and not (i==1 and j==slen)
+    local matched = not ((m_only or last_index==1) and not i)
+    if (hit_value == 1 and word_fail) or line_fail then
+      matched,i,j = false
+    end
+    if invert_match == matched then break end
+    if max_matches == 0 then os.exit(1) end
+    any_hit_ec = 0
+    m.hits, hit_value = m.hits + hit_value, 0
+    if f_only or no_only then
+      m.close = true
+    end
+    if flush or quiet then return end
+    if needs_filename then
+      write(m.label, LABEL_COLOR)
+      write(':', COLON_COLOR)
+      needs_filename = nil
+    end
+    if needs_line_num then
+      write(m.line_num, LINE_NUM_COLOR)
+      write(':', COLON_COLOR)
+      needs_line_num = nil
+    end
+    local s=m_only and '' or m.line:sub(last_index,(i or 0)-1)
+    local g=i and m.line:sub(i,j) or ''
+    if i==1 then g=trim_front(g) elseif last_index==1 then s=trim_front(s) end
+    if j==slen then g=trim_back(g) elseif not i then s=trim_back(s) end
+    write(s)
+    write(g, MATCH_COLOR)
+    empty_line = false
+    last_index = (j or slen)+1
+    if m_only or last_index>slen then
+      write("\n")
+      empty_line = true
+      needs_filename, needs_line_num = include_filename, print_line_num
+    elseif p:find("^^") and not plain then p="^$" end
+  end
+  if not empty_line then write("\n") end
+  if max_matches ~= math.huge and max_matches >= m.hits then
+    m.close = true
+  end
+end
+
+local uptime = computer.uptime
+local last_sleep = uptime()
+for meta,status in readLines() do
+  if uptime() - last_sleep > 1 then
+    os.sleep(0)
+    last_sleep = uptime()
+  end
+  if not meta then
+    if type(status) == 'table' then if flush then
+      flush(status) end -- this was the last object, closing out
+    elseif status then
+      ec = status or ec
+    end
+  else
+    for _,p in ipairs(PATTERNS) do
+      test(meta,p)
+    end
+  end
+end
+
+return ec or any_hit_ec