prevent writing file racing

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

@@ -275,9 +275,9 @@ Now you can input some space separated keywords (no order required) or use `CTRL
 
 Of course, you can always give more keywords to `z` command to match your destination precisely. `"z -I"` is similar to `"z -i"`, but use fzf. Both `"-i"` and `"-I"` provide you another way for path navigation.
 
-Usually, `z -I` can be aliased to `zf` (z + fuzzy finder) for convenience. If there are only one path matched, `z -I` will jump to it directly, fzf will only be invoked for multiple matches.
+Usually, `z -I` can be aliased to `zf` (z + fuzzy finder) for convenience. If there are only one path matched, `z -I` will jump to it directly, fzf will only be invoked for multiple matches. `"z -I ."` or `"zf ."` can be used to use fzf select from entire database. 
 
-`"z -I ."` or `"zf ."` can be used to use fzf select from entire database. Environment variable `_ZL_FZF_FLAG` is for passing additional arguments to fzf.
+For more information about this, please visit [wiki - effective with fzf](https://github.com/skywind3000/z.lua/wiki/Effective-with-fzf).
 
 NOTE: For fish shell, this feature requires fish 2.7.0 or above. You can specify fzf executable in `$_ZL_FZF` environment variable, `"fzf"` will be called by default.
 
@@ -458,6 +458,11 @@ As you see, z.lua is the fastest one and requires less resource.
 
 ## History
 
+- 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): `$_ZL_FZF_FLAG` can be used to override fzf flags, default to "+s -e".
 - 1.5.4 (2019-02-19): fixed: file/path existence detection fails on read-only fs (closed [#49](https://github.com/skywind3000/z.lua/issues/49) by [@contrun](https://github.com/contrun)).
 - 1.5.3 (2019-02-17): new `$_ZL_FZF_FLAG` for passing additional flags to fzf, add `-e` argument to fzf.
@@ -488,6 +493,7 @@ 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 1.5.5, Last Modified: 2019/02/20 12:07
+-- Version 1.5.10, Last Modified: 2019/03/01 13:08
 --
 -- * 10x faster than fasd and autojump, 3x faster than z.sh
 -- * available for posix shells: bash, zsh, sh, ash, dash, busybox
@@ -770,6 +770,10 @@ end
 -----------------------------------------------------------------------
 function os.environ(name, default)
 	local value = os.getenv(name)
+	if os.envmap ~= nil and type(os.envmap) == 'table' then
+		local t = os.envmap[name]
+		value = (t ~= nil and type(t) == 'string') and t or value
+	end
 	if value == nil then
 		return default
 	elseif type(default) == 'boolean' then
@@ -956,11 +960,16 @@ function data_save(filename, M)
 		fp = io.open(filename, 'w')
 	else
 		math.random_init()
-		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)
+		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 '')
+			if not os.path.exists(tmpname) then
+				-- print('tmpname: '..tmpname)
+				break
+			end
+		end
 		fp = io.open(tmpname, 'w')
 	end
 	if fp == nil then
@@ -1427,6 +1436,9 @@ function z_cd(patterns)
 	elseif Z_INTERACTIVE == 0 then
 		return M[1].name
 	end
+	if os.environ('_ZL_INT_SORT', false) then
+		table.sort(M, function (a, b) return a.name < b.name end)
+	end
 	local retval = nil
 	if Z_INTERACTIVE == 1 then
 		PRINT_MODE = '<stderr>'
@@ -1454,8 +1466,9 @@ 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
@@ -1547,6 +1560,7 @@ 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
@@ -1997,9 +2011,10 @@ function z_shell_init(opts)
 		end
 		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%'
+			fzf_cmd = "fzf --nth 2.. --reverse --inline-info --tac "
+			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