optimize with ffi (luajit builtin module).

Use \which in case user has it aliased to type -a

README.cn.md

@@ -269,7 +269,7 @@ PS：你可以使用 `$_ZL_FZF` 环境变量来精确指明 fzf 的可执行路
 - **(单个参数)**：`cd` 到离当前目录最近的以关键字开头的父目录，如果找不到就尝试跳到包含关键字的父目录。
 - **(两个参数)**：将当前路径中的第一个关键词替换为第二个关键词。
 
-为了使用简便，我们继续将 `z -b` 取个别名成 `zb`：
+先将 `z -b` 别名成 `zb`：
 
 ```bash
 # 一直向上退到项目根目录（就是里面有一个 .git 目录的地方）
@@ -350,23 +350,22 @@ $ z -
   => cd -
 ```
 
-这个 `dirstack` 是根据 z.lua 的路径历史数据库计算的出来的，所以和具体的 shell 或者操作系统都没有关系。你退出再登陆不会丢失这些路径历史，不同的 shell 之间也可以共享同一份历史数据。
+这个 `dirstack` 是根据 z.lua 的路径历史数据库计算的出来的，和具体的 shell 或者操作系统无关。你退出再登陆不会丢失这些记录，不同的 shell 之间也可以共享同一份记录。
 
-此外，还有另外一种方法，通过使用前面提到的 `-I` 和 `-t` 参数组和，可以使用 fzf 进行交互式选择：
+此外，还能通过前面提到的 `-I` 和 `-t` 参数组和，使用 fzf 选择最近去过的目录：
 
 ```bash
 alias zh='z -I -t .'
 ```
 
-首先定义个新的别名 `zh`（回到历史路径的意思），我们使用了 `-t` 参数来告诉 `z.lua` 按照时间戳作为权重进行排序，同时 `-I` 启用 fzf 进行搜索，最后的句号代表任意路径。
+方便起见，定义个新的别名 `zh`（回到历史路径的意思），我们用 `-t` 参数来告诉 `z.lua` 按时间戳为权重排序，同时 `-I` 启用 fzf 搜索，最后句号代表任意路径。
 
-那么当我们在命令行敲入 zh 时，就可以用 fzf 选择最近呆过的路径了：
+那么当我们在命令行敲入 zh 时，就可以用 fzf 进行历史路径操作了：
 
 ![](images/mru.png)
 
-第一列数据代表该路径多少秒以前访问过，第二列是路径名称。此时，你可以试着敲几个字母，用 fzf 的字符串模糊匹配进行定位，或者用光标键的上和下（CTRL+J/K 也可以）来上下移动，最后按回车 cd 过去，或者 ESC 放弃。
+第一列上次访问距今多少秒，第二列是目录名。你可以试着敲几个字母，用 fzf 的字符串模糊匹配进行定位，或者用光标键的上和下（CTRL+J/K 也可以）来上下移动，最后按回车 cd 过去，或者 ESC 放弃。
 
-注意：最好把增强匹配模式打开，这样查看历史路径时可以把当前路径过滤掉。
 
 
 ## Tips

README.md

@@ -458,6 +458,11 @@ As you see, z.lua is the fastest one and requires less resource.
 
 ## History
 
+- 1.6.0 (2019-03-04): optimize with ffi module (luajit builtin module).
+- 1.5.11 (2019-03-02): fixed: os.path.isdir doesn't work for symbol link folders.
+- 1.5.10 (2019-03-01): Prevent writing file racing.
+- 1.5.9 (2019-02-25): `z -b` should not match current directory (close #56).
+- 1.5.8 (2019-02-21): new `$_ZL_FZF_HEIGHT` to control `--height` parameter in fzf.
 - 1.5.7 (2019-02-21): rename `$_ZL_FZF_SORT` to `$_ZL_INT_SORT` it will affect both `-i` and `-I`.
 - 1.5.6 (2019-02-20): set `$_ZL_FZF_SORT` to 1 to sort directories by alphabet in fzf.
 - 1.5.5 (2019-02-20): `$_ZL_FZF_FLAG` can be used to override fzf flags, default to "+s -e".
@@ -490,6 +495,7 @@ As you see, z.lua is the fastest one and requires less resource.
 
 This project needs help for the tasks below:
 
+- [ ] Support csh/tcsh.
 - [ ] Completion: Actually I got little knowledge in completion, and need help to improve it.
 - [ ] Completion: Implement completion for Power Shell.
 - [ ] Completion: Implement completion for different arguments.

z.lua

@@ -4,7 +4,7 @@
 -- z.lua - a cd command that learns, by skywind 2018, 2019
 -- Licensed under MIT license.
 --
--- Version 1.5.7, Last Modified: 2019/02/21 11:07
+-- Version 1.6.0, Last Modified: 2019/03/04 14:47
 --
 -- * 10x faster than fasd and autojump, 3x faster than z.sh
 -- * available for posix shells: bash, zsh, sh, ash, dash, busybox
@@ -302,10 +302,107 @@ function os.log(text)
 end
 
 
+-----------------------------------------------------------------------
+-- ffi optimize (luajit has builtin ffi module)
+-----------------------------------------------------------------------
+os.native = {}
+os.native.status, os.native.ffi =  pcall(require, "ffi")
+if os.native.status then
+	local ffi = os.native.ffi
+	if windows then
+		ffi.cdef[[
+		int GetFullPathNameA(const char *name, uint32_t size, char *out, char **name);
+		int ReplaceFileA(const char *dstname, const char *srcname, void *, uint32_t, void *, void *);
+		uint32_t GetTickCount(void);
+		uint32_t GetFileAttributesA(const char *name);
+		uint32_t GetCurrentDirectoryA(uint32_t size, char *ptr);
+		]]
+		local kernel32 = ffi.load('kernel32.dll')
+		local buffer = ffi.new('char[?]', 300)
+		local INVALID_FILE_ATTRIBUTES = 0xffffffff
+		local FILE_ATTRIBUTE_DIRECTORY = 0x10
+		os.native.kernel32 = kernel32
+		function os.native.GetFullPathName(name)
+			local hr = kernel32.GetFullPathNameA(name, 290, buffer, nil)
+			return (hr > 0) and ffi.string(buffer, hr) or nil
+		end
+		function os.native.ReplaceFile(replaced, replacement)
+			local hr = kernel32.ReplaceFileA(replaced, replacement, nil, 2, nil, nil)
+			return (hr ~= 0) and true or false
+		end
+		function os.native.GetTickCount()
+			return kernel32.GetTickCount()
+		end
+		function os.native.GetFileAttributes(name)
+			return kernel32.GetFileAttributesA(name)
+		end
+		function os.native.exists(name)
+			local attr = os.native.GetFileAttributes(name)
+			return attr ~= INVALID_FILE_ATTRIBUTES
+		end
+		function os.native.isdir(name)
+			local attr = os.native.GetFileAttributes(name)
+			local isdir = FILE_ATTRIBUTE_DIRECTORY
+			if attr == INVALID_FILE_ATTRIBUTES then
+				return false
+			end
+			return (attr % (2 * isdir)) >= isdir
+		end
+		function os.native.getcwd()
+			local hr = kernel32.GetCurrentDirectoryA(299, buffer)
+			if hr <= 0 then return nil end
+			return ffi.string(buffer, hr)
+		end
+	else
+		ffi.cdef[[
+		typedef struct { long tv_sec; long tv_usec; } timeval;
+		int gettimeofday(timeval *tv, void *tz);
+		int access(const char *name, int mode);
+		char *realpath(const char *path, char *resolve);
+		char *getcwd(char *buf, size_t size);
+		]]
+		local timeval = ffi.new('timeval[?]', 1)
+		local buffer = ffi.new('char[?]', 4100)
+		function os.native.gettimeofday()
+			local hr = ffi.C.gettimeofday(timeval, nil)
+			local sec = tonumber(timeval[0].tv_sec)
+			local usec = tonumber(timeval[0].tv_usec)
+			return sec + (usec * 0.000001)
+		end
+		function os.native.access(name, mode)
+			return ffi.C.access(name, mode)
+		end
+		function os.native.realpath(name)
+			local path = ffi.C.realpath(name, buffer)
+			return (path ~= nil) and ffi.string(buffer) or nil
+		end
+		function os.native.getcwd()
+			local hr = ffi.C.getcwd(buffer, 4099)
+			return hr ~= nil and ffi.string(buffer) or nil
+		end
+	end
+	function os.native.tickcount() 
+		if windows then
+			return os.native.GetTickCount()
+		else
+			return math.floor(os.native.gettimeofday() * 1000)
+		end
+	end
+	os.native.init = true
+end
+
+
 -----------------------------------------------------------------------
 -- get current path
 -----------------------------------------------------------------------
 function os.pwd()
+	if os.native and os.native.getcwd then
+		local hr = os.native.getcwd()
+		if hr then return hr end
+	end
+	if os.getcwd then
+		return os.getcwd()
+	end
 	if windows then
 		local fp = io.popen('cd')
 		if fp == nil then
@@ -372,6 +469,10 @@ end
 -----------------------------------------------------------------------
 function os.path.abspath(path)
 	if path == '' then path = '.' end
+	if os.native and os.native.GetFullPathName then
+		local test = os.native.GetFullPathName(path)
+		if test then return test end
+	end
 	if windows then
 		local script = 'FOR /f "delims=" %%i IN ("%s") DO @echo %%~fi'
 		local script = string.format(script, path)
@@ -427,13 +528,17 @@ function os.path.isdir(pathname)
 	elseif windows then
 		if pathname == '\\' then
 			return true
-		elseif pathname:match('^%a:[/\\]$') then
-			return true
 		end
 	end
+	if os.native and os.native.isdir then
+		return os.native.isdir(pathname)
+	end
+	if clink and os.isdir then
+		return os.isdir(pathname)
+	end
 	local name = pathname
 	if (not name:endswith('/')) and (not name:endswith('\\')) then
-		name = name .. '/'
+		name = name .. os.path.sep
 	end
 	return os.path.exists(name)
 end
@@ -453,6 +558,12 @@ function os.path.exists(name)
 				io.close(f)
 				return true
 			end
+		elseif name:sub(-1) == '/' and code == 20 and (not windows) then
+			local test = name .. '.'
+			ok, err, code = os.rename(test, test)
+			if code == 16 or code == 13 or code == 22 then
+				return true
+			end
 		end
 		return false
 	end
@@ -867,6 +978,9 @@ function math.random_init()
 		seed = seed .. rnd
 	end
 	seed = seed .. tostring(os.clock() * 10000000)
+	if os.native and os.native.tickcount then
+		seed = seed .. tostring(os.native.tickcount())
+	end
 	local number = 0
 	for i = 1, seed:len() do
 		local k = string.byte(seed:sub(i, i))
@@ -956,15 +1070,29 @@ function data_save(filename, M)
 	local tmpname = nil
 	local i
 	filename = os.path.expand(filename)
-	if windows then
-		fp = io.open(filename, 'w')
-	else
-		math.random_init()
+	math.random_init()
+	while true do
 		tmpname = filename .. '.' .. tostring(os.time())
-		tmpname = tmpname .. math.random_string(8)
-		local rnd = os.getenv('_ZL_RANDOM')
-		tmpname = tmpname .. '' .. (rnd and rnd or '')
-		-- print('tmpname: '..tmpname)
+		if os.native and os.native.tickcount then
+			local key = os.native.tickcount() % 1000
+			tmpname = tmpname .. string.format('%03d', key)
+			tmpname = tmpname .. math.random_string(5)
+		else
+			tmpname = tmpname .. math.random_string(8)
+		end
+		if not os.path.exists(tmpname) then
+			-- print('tmpname: '..tmpname)
+			break
+		end
+	end
+	if windows then
+		if os.native and os.native.ReplaceFile then
+			fp = io.open(tmpname, 'w')
+		else
+			fp = io.open(filename, 'w')
+			tmpname = nil
+		end
+	else
 		fp = io.open(tmpname, 'w')
 	end
 	if fp == nil then
@@ -977,7 +1105,11 @@ function data_save(filename, M)
 	end
 	fp:close()
 	if tmpname ~= nil then
-		os.rename(tmpname, filename)
+		if windows then
+			os.native.ReplaceFile(filename, tmpname)
+		else
+			os.rename(tmpname, filename)
+		end
 		os.remove(tmpname)
 	end
 	return true
@@ -1461,8 +1593,9 @@ function z_cd(patterns)
 		cmd = ((fzf == '') and 'fzf' or fzf)  .. ' ' .. cmd .. ' ' .. flag
 		if not windows then
 			tmpname = os.tmpname()
-			if not os.environ('_ZL_FZF_FULLSCR', false) then
-				cmd = cmd .. ' --height 35%'
+			local height = os.environ('_ZL_FZF_HEIGHT', '35%')
+			if height ~= nil and height ~= '' and height ~= '0' then
+				cmd = cmd .. ' --height ' .. height
 			end
 			cmd = cmd .. ' < "' .. tmpname .. '"'
 		else
@@ -1554,6 +1687,7 @@ function cd_backward(args, options, pwd)
 			end
 			return os.path.normpath(path)
 		else
+			pwd = os.path.split(pwd)
 			local test = windows and pwd:gsub('\\', '/') or pwd
 			local key = windows and args[1]:lower() or args[1]
 			if not key:match('%u') then
@@ -2005,8 +2139,9 @@ function z_shell_init(opts)
 		print(script_complete_bash)
 		if opts.fzf ~= nil then
 			fzf_cmd = "fzf --nth 2.. --reverse --inline-info --tac "
-			if not os.environ('_ZL_FZF_FULLSCR', false) then
-				fzf_cmd = fzf_cmd .. ' --height 35%'
+			local height = os.environ('_ZL_FZF_HEIGHT', '35%')
+			if height ~= nil and height ~= '' and height ~= '0' then
+				fzf_cmd = fzf_cmd .. ' --height ' .. height .. ' '
 			end
 			local flag = os.environ('_ZL_FZF_FLAG', '')
 			flag = (flag == '' or flag == nil) and '+s -e' or flag

z.lua.plugin.zsh

@@ -6,14 +6,14 @@ ZLUA_SCRIPT="${0:A:h}/z.lua"
 
 # search lua executable
 if [[ -z "$ZLUA_EXEC" ]]; then
-	if [[ -x "$(which lua)" ]]; then
-		ZLUA_EXEC="$(which lua)"
-	elif [[ -x "$(which lua5.3)" ]]; then
-		ZLUA_EXEC="$(which lua5.3)"
-	elif [[ -x "$(which lua5.2)" ]]; then
-		ZLUA_EXEC="$(which lua5.2)"
-	elif [[ -x "$(which lua5.1)" ]]; then
-		ZLUA_EXEC="$(which lua5.1)"
+	if [[ -x "$(command which lua)" ]]; then
+		ZLUA_EXEC="$(command which lua)"
+	elif [[ -x "$(command which lua5.3)" ]]; then
+		ZLUA_EXEC="$(command which lua5.3)"
+	elif [[ -x "$(command which lua5.2)" ]]; then
+		ZLUA_EXEC="$(command which lua5.2)"
+	elif [[ -x "$(command which lua5.1)" ]]; then
+		ZLUA_EXEC="$(command which lua5.1)"
 	else
 		echo "Not find lua in your $PATH, please install it."
 		return