What I know about batch files

23

September 24, 2014 by Kenneth Fisher

For a SQL Server guy it sometimes amazes me how often I’m in and out of batch files and how truly useful they can be. To that end here is all that I can remember about batch files (basically a text file that ends with .bat). Everyone seemed to like 15 years of experience with identity columns so I’m doing this in that same format. Also in the same way please feel free to comment with what you can remember and corrections for any mistakes you find.

  • To create a batch file type batch commands into a text file and name it with a .bat extension.
  • To run a batch file either double click on it in windows explorer, right click and hit Open, or type the name in a command shell (in the correct directory) and hit enter.
  • ECHO ON to print the commands to the output.
  • ECHO OFF to stop printing commands to the output.
  • ECHO <message> will write <message> to the output.
  • REM comments out a line. This line will be printed if ECHO is turned on.
  • :: Also comments out the line but will not be printed if ECHO is turned on.
  • You can pass in parameters by putting %1, %2, %3 etc in your bat file. These will corrispond to the 1st, 2nd, and 3rd parameters passed in to a limit of %9.
  • %* is all parameters.
  • SHIFT moves the parameters down one. So the second parameter is now %1, third parameter is %2 etc. This let’s you handle more than 9 parameters.
  • If you call the parameters like this %~1, %~2, %~3 then the quotes(“”) surrounding the parameter will be stripped off.
  • SET var=xxx xxx Declares the variable var and stores “xxx xxx” into it.
  • ECHO %var% to print the contents of the variable var.
  • Put :<labelname> at the beginning of a line to create a label.
  • Use GOTO :<labelname> to jump to that label.
  • IF condition (command) Run command if condition is true.
  • IF EXIST <filename> command Run command if <filename> exists.
  • NOT <condition> Checks if the condition is not true.
  • Use == For equal to.
  • Use <> or != for not equal to.
  • CD <path> change location to <path>.
  • <driveletter>: Change location to current directory of <driveletter>.
  • . is the current directory.
  • .. is the directory one above the current directory.
  • COPY <file1> <Location1> Copies the file <file1> to <Location1>.
  • COPY <file1> +<file2> Copies the contents of <file2> into <file1>.
  • MOVE <file1> <location1> Moves the file <file1> to <location1>.
  • DEL <filename> Deletes <filename> if it exists.
  • TYPE <file1> prints the contents of <file1> to the output.
  • CALL <batchfile> Executes <batchfile>.
  • START <command/program> Starts a command or program.
  • <command1> | <command2> passes the output of <command1> to <command2>.
  • ECHO |TIME or ECHO |DATE prints the time or date to the output.
  • FIND “<string>” outputs only the lines with <string> in them from whatever input is passed.
  • DIR |FIND “mystring” outputs only the rows with mystring from the DIR command.
  • DIR > test.txt Copies the output of the DIR command to the file test.txt overwriting the file if it already exists.
  • EXIT <errorlevel> to leave the bat file and return <errorlevel> to the calling code. <errorlevel> is optional.

23 thoughts on “What I know about batch files

  1. Brandon Champion says:

    @ sets ECHO OFF for the current line.

    @ECHO OFF is usually the first line of my batch files.

  2. Ron Van Aken says:

    Kenneth,

    Thank you for sharing. You’ve got some good stuff here that will likely add to anyone’s bag of batch file tricks. I hadn’t seen some of these before. It’s good to have a crib-sheet like this for reference.

    I’ll contribute one I didn’t see (the for statement):

    dir \\BuildServer\BuildArea\2.0.*.0 /A:D /B /O:-N >dir.txt
    Set Version=
    for /F %%i in (dir.txt) do set Version=%%i

    The above saves a sorted directory of folders to a file, and sets a variable with the last value.

    You should take a look at PowerShell. It will blow your mind!

    Thanks again,

    Ron

  3. William K. Bennett says:

    Thank you for a great reference.

    Here’s another little goodie:

    Dir >> test.txt appends the output of the Dir command to the file, rather than overwriting it. This also works for Type, and any other command that can be redirected.

    Bill

  4. TYPE | more
    MORE <
    prints the contents of to the output but 1 page a time. The first line is more typework but safer because if you type MORE > you overwrite your file.

    XCOPY /R : copy entire subdirectories and its subdirectories. But it is deprecated. On newer systems better use ROBOCOPY.

    SET DIRCMD= : if you always use certain parameters for your dir, you can put them in the SET DIRCMD so they become the default.

    PROMPT: change the dos-prompt.

    DISKCOPY : copy a floppy disk (does anyone still use those????? 🙂 )

    SHUTDOWN : shuts down the computer (without parameters, it just shows the parameters!)

    TASKKILL : kill a process. You can use the processid or the name of the process.

    HELP: shows the doscommands that exist.

    xxxxx /? : to get help on the parameters of any command

    CLS : clear the screen to clean up the mess. Works also in Powershell.

    RUNAS : to run something using other credentials then the current ones

    echo xxx > : write the output to file OVERWRITING the file
    echo xxx >> : write the output to file ADDING it to the file if it exists.
    somecommand > %1> : writes the output of the command in file1 and writes the errors in file 2.
    Ex:
    echo|date > c:\z\x.txt %1> c:\z\xx.txt
    The echo|date gives an error and it will be written file xx.txt

    I really like the ECHO |TIME o DATE trick. After +- 25 years of DOS, I didn’t know that trick. I used this
    date < with in only a CR/LF.

    How to create a file with CR/LF in it?
    COPY CON c:\x\crlf.txt
    Then hit the return-key (don’t mind the message if the file already exists and answer Yes) and then hit F6 and enter. (you copy from the console to a file, so everything you type will be copied into the file. F6+enter will close the file)

  5. Chris Nelson says:

    In some situations it’s easier to get permission to run a batch file than a PS script.

    Here’s a good routine I found elsewhere on the internet for renaming files with a date stamp.

    ren Daily_File.zip Daily_File_%date:~-4,4%%date:~-10,2%%date:~-7,2%.zip

  6. Kelly Schlueter says:

    I have done a lot of automation with batch files. Here are some things that I have found very useful.

    Call : parm1 parm2 – This effectively calls as a subroutine.
    Goto :EOF – This is a return from a Call.

    In use, the pattern looks like this:
    ——————————————–
    Call : Param1 Param2 …

    Goto :EOF

    :
    :: Parameters passed to the subroutine look like command line parameters.
    Echo %1 – Param1
    Echo %2 – Param2

    Goto :EOF
    ——————————————–

    Here are a few other useful techniques:
    Echo. – This echos a blank line.

    Set EnvVar=%EnvVar:ExistingWord=NewWord – This replaces a given substring in the environment variable

    If /I “%EnvVar%”==”%EnvVar:ExistingWord=%” … – This checks if a substring is in the environment variable.

    %EnvVar:~1,5% – This extracts a substring from the environment variable.

    %~f1 expands %1 to a fully qualified path name
    %~d1 expands %1 to a drive letter
    %~p1 expands %1 to a path
    %~n1 expands %1 to a file name
    %~x1 expands %1 to a file extension
    %~s1 expanded path containing 8.1 short names only
    %~a1 expands %1 to file attributes
    %~t1 expands %1 to date/time of file
    %~z1 expands %1 to size of file

    Here is another pattern that I use a lot for automation:

    Set CmdLine=type “path\Input File.txt”
    For /f “tokens=1,2,3* delims=,” %%a In (‘%CmdLine%’) Do Call :ProcessLines “%%a” “%%b” “%%c”

    This is a very powerful pattern. It executes the command in the CmdLine variable. It then spins through each line of output parsing it according to the delims list. It then breaks each line into however many chunks are specified by the tokens list putting the results in consecutive variables starting with the specified letter. It then executes whatever follows the “Do” keyword once for each line of output being parsed.

    CmdLine can be any command line that can be executed at a command prompt includes console applications. If delims are left out, the default delimiter is space. Star in the tokens list means to include the rest of the line.

  7. Dexter Jones says:

    Nice list.
    Don’t forget the humble Pause statement.
    Sometimes it’s nice to give your user (or you) the option to bail out of the batch file.

  8. or in case you don’t want the output
    ping -n 5 127.0.0.1 > nul:

  9. Richard says:

    If you need the path of the currently executing batch file:

    %~dp0

    Found at: lifehacker.com/5310255/use-relative-paths-in-your-batch-files

  10. Bruce says:

    In more recent versions of Windows I’ve started using TIME /T and DATE /T for time and date strings.

  11. […] means I pipe (|) information from one command to another. Something which is very natural to anyone used to DOS & bat files. In this particular case I’ve piped the output of Get-ChildItem to Where-Object in order to […]

  12. […] easily be used to run a script or stored procedure on a remote SQL Server. Combining this with a bat file (yes, again older technology) and an Enterprise scheduler (because not all of us use SQL Server […]

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