Difference between revisions of "Batch"

Revision as of 10:54, 21 March 2011

Batch files are the original ms-dos scripting language. A batch file is a script that contains a list of ms-dos commands, with one command per line. When you try to execute the batch file, it will execute the ms-dos commands, one after another, waiting for each command to finish before starting the next one.

Examples

For

The following example will output each line of the text file to the stdout:

> FOR /F %i in (list.txt) DO @echo %~ni

The following example will allow to parse and edit the environment variables (invoke the command line with CMD /V):

> for /F %i in ('dir /B /S *_1.dat') do @set subs=21 @set fil=%i & copy /Y !fil! !fil:20=%subs%!

If you want to write FOR loops in a batch file instead of the command line, then use %%i instead of %i.

To place the first line of a file into a variable:

> SET /P _MyVar=<MyFilename.txt

To place the last line of a file into a variable:

> FOR /F "tokens=*" %A IN (C:\boot.ini) DO SET TestVar=%A

Nested FOR Loops

> FOR /F %a IN (filelist.txt) DO (FOR /F %b IN (salinitytemperature.txt) DO echo %a %b)

Nested FOR loops encapsulated in a batch file

for /F %%a in (%1) do (
    for /R %%b in (../*) do (
        echo %%a
        echo %%b
    )
)

Delimeters

This command will look for the first underscore in the list of filenames and will split each filename in two at the underscore.

> for /f "tokens=1-4 delims=_" %i in ('dir /B *.eps') do @echo  %i %j %k %l

Check out this site for more.

Misc

Manipulating environment variables

Substring find and replace

> set HELLO=HelloWorld
> echo %HELLO:l=w%
echo> HewwoWorwd

Extension stripping

> For /F %%i in (list.txt) DO echo %%~ni

See more help

>set /?

Escaping characters

<,|,> and % characters are special characters in dos. To escape them use the ^ character or a double %

> echo ^<example^>
<example>

Displaying blank lines

Use command echo to display a blank line instead of its default status result

>echo.

Sample applications

Copy a clean MOHID project

Here's a combination with a batch file, that creates a clean copy of a MOHID simulation:

> copysimulation MySimulation

#copysimulation.bat content
#Input argument %1 stands for simulation name
@echo off
set COPYHOME=C:\Program Files\2gif
xcopy %1\*.* %1_copy /E /EXCLUDE:%COPYHOME%\exclui.txt
perl %COPYHOME%/replace.pl 's/%2/\.\.\/\.\./g' *
perl %COPYHOME%/replace.pl 's/\\/\//g' *
@echo on

Remove all openmp directives from the code

NOTE: cygwin or gnuwin32 with all the gnu tools executables must be installed and accessible from the path command line.

$ for /F %i in ('dir /B /S *.F90') do @cat %i | grep -v !$OMP > %~ni.tpp
$ for /F %i in ('dir /B /S *.tpp') do @copy %i %~ni.F90
$ for /F %i in ('dir /B /S *.tpp') do @del %i

Appending hourly data files from Instituto Hidrográfico

for /F %i in ('dir /B *') DO @type %i | grep MCAS >> one-file.txt

Duplicating a Run in a MOHID Simulation

This batch file duplicates a run with a new number (and updates the Nomfich files correspondingly). It requires a CMD /V console calling and also the gnu utility Sed.

@echo off
REM DUPLICATE_RUN.BAT
REM ATTENTION: Must be run with the CMD /V option!
REM ARG1 %1 SOURCE RUN ID
REM ARG2 %2 TARGET RUN ID

REM Duplicates the filenames
for /F "delims=*" %%i in ('dir /S /B *_%1.dat') do (
	set NAME=%%i
	@echo Created !NAME:%1=%2!
	copy /Y "!NAME!" "!NAME:%1=%2!"
)

REM Updates the nomfich_N.dat files
for /F %%i in ('dir /S /B Nomfich_%2.dat') do (
	sed -e "s/%1/%2/g" %%i > %%i.bak
	move /Y %%i.bak %%i
)

Set a run number

echo off
REM REM ATTENTION: Must be run with the CMD /V option!
REM ARG1 %1 SOURCE RUN ID

REM Activate the chosen run
for /F %%i in ('dir ..\*Nomfich.dat /S /B ') do (
	REM @echo copy /Y %%~di%%~pi..\dat\Nomfich_%1.dat %%i
	set MYDIR=%%~di%%~pi
	copy /Y !MYDIR:~0,-4!data\Nomfich_%1.dat %%i
)

External References

• Batch files tutorial;
• for command reference;
• windows nt command-line reference;
• gnuwin32 download