Windows批处理文件有哪些不太为人所知,但很重要和有用的特性?

指南:

每个答案一个特征 给出特性的简短描述和示例,而不仅仅是文档链接 将答案限制在本地功能,即不需要额外的软件,如Windows资源包

澄清:这里我们指的是由cmd.exe处理的脚本,这是WinNT变体的默认值。

(请参见:Windows批处理文件:.bat vs .cmd?)


当前回答

FIND作为grep的替代品。 我用find给自己黑了个电话簿。非常有用:

@echo off
:begin
set /p term=Enter query: 
type phonebookfile.txt |find /i "%term%"
if %errorlevel% == 0 GOTO :choose
echo No entry found
set /p new_entry=Add new entry: 
echo %new_entry% >> phonebookfile.txt 
:choose
set /p action=(q)uit, (n)ew query or (e)dit? [q] 
if "%action%"=="n" GOTO anfang
if "%action%"=="e" (
    notepad phonebookfile.txt
    goto :choose
)

非常快速有效。

其他回答

设置环境变量时的搜索和替换:

> @set fname=%date:/=%

...从日期中删除“/”以用于带时间戳的文件名。

还有子字符串……

> @set dayofweek=%fname:~0,3%

将输出重定向到控制台,即使批处理的输出已经通过> con语法重定向到文件。

例子: foo.cmd:

echo a
echo b > con

调用:

foo.cmd > output.txt

这将导致“a”输出到output.txt,而“b”输出到控制台。

CHOICE命令提示用户在多个选项中选择一个(通过单个按键)

@echo off
echo Please choose one of the following options
echo 1. Apple
echo 2. Orange
echo 3. Pizza
echo a, b, c. Something else
choice /c:123abc /m "Answer?"
set ChoiceLevel=%ErrorLevel%
echo Choice was: %ChoiceLevel%

%ChoiceLevel%将是选中的第n个选项(在上面的例子中,b=5)。

更多详情请访问SS64.com上的CHOICE参考页面。

关于使用::而不是REM进行评论:要小心!::是CALL标签的一种特殊情况,作用类似于注释。当在括号内使用时,例如在for或IF循环中,函数将提前退出。调试非常令人沮丧!

详细描述请参见http://www.ss64.com/nt/rem.html。

(添加一个新的答案,而不是上面第一次提到的评论,因为我还不值得评论:0)

抽取随机的文本行

@echo off

:: Get time (alas, it's only HH:MM xM

for /f %%a in ('time /t') do set zD1=%%a



:: Get last digit of MM

set zD2=%zD1:~4,1%



:: Seed the randomizer, if needed

if not defined zNUM1 set /a zNUM1=%zD2%


:: Get a kinda random number

set /a zNUM1=zNUM1 * 214013 + 2531011

set /a zNUM2=zNUM1 ^>^> 16 ^& 0x7fff


:: Pull off the first digit

:: (Last digit would be better, but it's late, and I'm tired)

set zIDX=%zNUM2:~0,1%


:: Map it down to 0-3

set /a zIDX=zIDX/3


:: Finally, we can set do some proper initialization

set /a zIIDX=0

set zLO=

set zLL=""


:: Step through each line in the file, looking for line zIDX

for /f "delims=@" %%a in (c:\lines.txt) do call :zoo  %zIDX%  %%a


:: If line zIDX wasn't found, we'll settle for zee LastLine

if "%zLO%"=="" set zLO=%zLL%

goto awdun


:: See if the current line is line zIDX

:zoo


:: Save string of all parms

set zALL=%*


:: Strip off the first parm (sure hope lines aren't longer than 254 chars)

set zWORDS=%zALL:~2,255%


:: Make this line zee LastLine

set zLL=%zWORDS%


:: If this is the line we're looking for, make it zee LineOut

if {%1}=={%zIIDX%} set zLO=%zWORDS%


:: Keep track of line numbers

set /a zIIDX=%zIIDX% + 1

goto :eof




:awdun

echo ==%zLO%==


:: Be socially responsible

set zALL=

set zD1=

set zD2=

set zIDX=

set zIIDX=

set zLL=

set zLO=

:: But don't mess with seed

::set zNUM1=

set zNUM2=

set zWORDS=