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?)
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
这个批处理文件既可以使用简单文件,也可以使用目录作为命令行参数(您可以以任何顺序混合它们)。循环在任何指定的文件上运行命令(本例中为'echo'),如果一个参数是一个目录,它将在其中的每个文件上递归地运行命令。
@echo off
for /f "delims=" %%f in ('dir %* /a-d /b /s') do echo %%f
其他回答
批处理脚本最常见的需求之一是记录生成的输出,以供以后检查。是的,您可以将stdout和stderr重定向到一个文件,但是您无法看到发生了什么,除非您跟踪日志文件。
因此,考虑使用stdout/stderr日志记录工具运行您的批处理脚本,例如logger,它将使用时间戳记录输出,并且您仍然能够看到脚本进程。
另一个stdout/stderr日志记录实用程序
Yet another stdout/stderr logging utility [2010-08-05]
Copyright (C) 2010 LoRd_MuldeR <MuldeR2@GMX.de>
Released under the terms of the GNU General Public License (see License.txt)
Usage:
logger.exe [logger options] : program.exe [program arguments]
program.exe [program arguments] | logger.exe [logger options] : -
Options:
-log <file name> Name of the log file to create (default: "<program> <time>.log")
-append Append to the log file instead of replacing the existing file
-mode <mode> Write 'stdout' or 'stderr' or 'both' to log file (default: 'both')
-format <format> Format of log file, 'raw' or 'time' or 'full' (default: 'time')
-filter <filter> Don't write lines to log file that contain this string
-invert Invert filter, i.e. write only lines to log file that match filter
-ignorecase Apply filter in a case-insensitive way (default: case-sensitive)
-nojobctrl Don't add child process to job object (applies to Win2k and later)
-noescape Don't escape double quotes when forwarding command-line arguments
-silent Don't print additional information to the console
-priority <flag> Change process priority (idle/belownormal/normal/abovenormal/high)
-inputcp <cpid> Use the specified codepage for input processing (default: 'utf8')
-outputcp <cpid> Use the specified codepage for log file output (default: 'utf8')
我发现你可以轻松地将命令输出重定向到文件中非常有用:
DIR *.txt > tmp.txt
DIR *.exe >> tmp.txt
单箭头创建或覆盖文件,双箭头追加文件。现在我可以在我的文本编辑器中打开tmp.txt,做各种各样的事情。
狡猾的等待N秒的技巧(不是cmd.exe的一部分,但不是额外的软件,因为它是Windows自带的),参见ping行。您需要N+1个ping,因为第一个ping没有延迟。
echo %time%
call :waitfor 5
echo %time%
goto :eof
:waitfor
setlocal
set /a "t = %1 + 1"
>nul ping 127.0.0.1 -n %t%
endlocal
goto :eof
变量的延迟展开(为了更好地度量,还加入了子字符串):
@echo off
setlocal enableextensions enabledelayedexpansion
set full=/u01/users/pax
:loop1
if not "!full:~-1!" == "/" (
set full2=!full:~-1!!full2!
set full=!full:~,-1!
goto :loop1
)
echo !full!
endlocal
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=