Call a subroutine in a batch from another batch file - batch-file

Question

file1.bat:
#echo off
:Test
echo in file one
call file2.bat (Here i want to call only Demo routine in the file2.bat)
file2.bat:
:hello
echo in hello
:Demo
echo in Demo
From the batch file1 I want to make a call to a sub routine in the batch file2.
I tried for example call file2.bat:Demo but it didn't give the correct result.
How I can achieve this?

Answer 1

the file with subroutines must look like:
#echo off
call :%*
exit /b %errorlevel%
:hello
echo in hello
exit /b 0
:Demo
echo in Demo with argument %1
exit /b 0
then from the other file you can call it like
call file2.bat demo "arg-one"

Answer 2

You can write your functions file (in this sample it is library.cmd) as
#echo off
setlocal enableextensions
rem Not to be directly called
exit /b 9009
:test
echo test [%*]
goto :eof
:test2
echo test2 [%*]
goto :eof
:testErrorlevel
echo testErrorlevel
exit /b 1
And then the caller batch can be something like
#echo off
setlocal enableextensions disabledelayedexpansion
call :test arg1 arg2 arg3
call :test2 arg4 arg5 arg6
call :testErrorlevel && echo no errorlevel || echo errorlevel raised
goto :eof
:test
:test2
echo calling function %0
library.cmd %*
:testErrorlevel
echo calling function %0
library.cmd
In this case, the labels need to be defined with the same name in both files.
The direct invocation of the "library" batch file will replace the context of the call :label, and when the invoked batch is readed, a goto :label is internally executed and code continues inside the indicated label. When the called batch file ends, the context is released and the code after the call :label continues.
edited
As Jeb points in comments, there is a drawback in this method. The code running in the called batch file can not use %0 to retrieve the name of the function being called, it will return the name of the batch file. But if needed, the caller can do it as shown in the sample code.
edited 2016/12/27
Answering to dbenham, I have no way to know if it was a coding error or an intended feature, but this is how the process works
The lines in batch file are processed inside the inner BatLoop function when a batch "context" is created. This function receives, as one of its arguments, a pointer to the command that caused the "context" to be created.
Inside this function the commands in the batch file are iterated. The loop that iterates over the commands makes a test in each iteration: if extensions are enabled, it is the first line in the batch file and the arguments of the command that started the context starts with a colon (a label), a goto is generated to jump to the label.
Up to here, I have to suppose that this is the intended behaviour to handle the call :label syntax: create a new "context", load the file, jump to the label.
But the command argument received is never changed, a different variable is used to track the execution of the commands in the batch file. If a new batch file is loaded into / overwrites the current batch "context" (we have not used call command), after loading the new batch code, BatLoop resets the line count (we start at the first line of the loaded file) and, voila, the condition at the start of the loop (extensions enabled, first line, the colon) is true again (the pointed input command has not been changed) and a new goto is generated.

Answer 3

To comment a bit more, here is the code I came out reading the answer. It basically give you a 'utility' file where you can add your sub/fnc in a common library for code maintenance.
A) As a example, here is the 'utility_sub.cmd' file:
REM ==============================================
REM CALL THE SELECTED SUB
REM ==============================================
REM echo %~1
GOTO :%~1
REM ==============================================
REM ERROR MANAGEMENT
REM ==============================================
REM Ref : https://ss64.com/nt/exit.html
:RAISE_ERROR
EXIT /B 1
:RESET_ERROR
EXIT /B 0
REM Demo call
REM =========
REM CALL :RAISE_ERROR
REM echo RAISE_ERROR ERRORLEVEL = %ERRORLEVEL%
REM If %ERRORLEVEL% GTR 0 (
REM set msg="%tab%- Error detected ..."
REM CALL :SUB_STDOUT_MSG !msg!, 1
REM )
REM CALL :RESET_ERROR
REM echo RESET_ERROR ERRORLEVEL = %ERRORLEVEL%
REM ==============================================
REM SUB_STDOUT_MSG
REM ==============================================
:SUB_STDOUT_MSG
REM CALL :SUB_STDOUT_MSG "%param1%", %param2%, %param3%
REM Instead of this stdout sub, we can use Unix 'tee.exe'
REM but there is no 'line counter' feature like this sub
REM Call example :
REM EDI_Generate_Stat_Csv | tee c:\temp\voir.txt
REM Def :
REM Capture output from a program and also display the output to the screen, at the same time.
REM %~1 => Expand %1 removing any surrounding quotes (")
set msg=%~2
set sendtoLog=%3
set addCounter=%4
If !msg!==. (
REM Write empty line
echo!msg!
If !sendtoLog! EQU 1 (
echo!msg! >> %log_file%
)
) else (
REM (a) Write comment line (b) add counter if any
If !addCounter! EQU 1 (
set /a msgCounter+=1
set msg=!msgCounter! - !msg!
REM Pad counter left for single digit
If !msgCounter! LSS 10 (
set msg=0!msg!
)
)
REM Output to console
echo !msg!
REM Output to log
If !sendtoLog! EQU 1 (
echo !msg! >> %log_file%
)
)
EXIT /B
B) And here is how to call the 'SUB_STDOUT_MSG' in you 'main-logic' command file:
REM ... some other code here
REM ==============================================
REM PROGRAM END
REM ==============================================
set msg=.
CALL :SUB_STDOUT_MSG !msg!, 1
set msg="My programA - End"
CALL :SUB_STDOUT_MSG !msg!, 1
set msg="%date:~0,4%-%date:~5,2%-%date:~8,2% %time:~0,2%:%time:~3,2%:%time:~6,2%"
CALL :SUB_STDOUT_MSG !msg!, 1
set msg="+++++++++++++++"
CALL :SUB_STDOUT_MSG !msg!, 1
timeout 2 > Nul
REM Skip all SUB ROUTINE
GOTO :EOF
REM ==============================================
REM CALL SUB ROUTINE
REM ==============================================
:SUB_STDOUT_MSG
REM echo calling sub %0
CALL "C:\Utilitaires\Financement\Utility_Sub.cmd" SUB_STDOUT_MSG %*
EXIT /B
:EOF

Answer 4

What about providing the target label as the first agrument of the called script? You needed to modify the called dscript then though.
file1.bat (main):
#echo off
echo/
echo File "%~0": call "file2.bat" [no arguments]
call "file2.bat"
echo/
echo File "%~0": call "file2.bat" :DEMO
call "file2.bat" :DEMO
echo/
echo File "%~0": call "file2.bat" :DEMO A B C
call "file2.bat" :DEMO A B C
file2.bat (sub):
#echo off
set "ARG1=%~1" & if not defined ARG1 goto :TEST
if "%ARG1:~,1%"==":" goto %ARG1%
:TEST
echo File "%~nx0", :TEST; arguments: %*
goto :EOF
:DEMO
echo File "%~nx0", :DEMO; arguments: %*
echo before `shift /1`:
echo "%%~0" refers to "%~0"
echo "%%~1" refers to "%~1"
shift /1
echo after `shift /1`:
echo "%%~0" refers to "%~0"
echo "%%~1" refers to "%~1"
goto :EOF
Output:
>>> file1.bat
File "file1.bat": call "file2.bat" [no arguments]
File "file2.bat", :TEST; arguments:
File "file1.bat": call "file2.bat" :DEMO
File "file2.bat", :DEMO; arguments: :DEMO
before `shift /1`:
"%~0" refers to "file2.bat"
"%~1" refers to ":DEMO"
after `shift /1`:
"%~0" refers to "file2.bat"
"%~1" refers to ""
File "file1.bat": call "file2.bat" :DEMO A B C
File "file2.bat", :DEMO; arguments: :DEMO A B C
before `shift /1`:
"%~0" refers to "file2.bat"
"%~1" refers to ":DEMO"
after `shift /1`:
"%~0" refers to "file2.bat"
"%~1" refers to "A"