This is batch file..
Example
##@ Echo off
# set current directory using below cd command
set currentDir=%cd%
# set path to some temp variable, as we need to set it back to its old
value after our operation is done.
set oldPath=%PATH%
# now append/combine system environment path variable and our current directory path
set PATH=%PATH%;C:\Program Files (x86)\Microsoft\ILMerge;.;%currentDir%\..\App\Source\.nuget
@Echo on
MD .\App\Lib\net40
MD .\Messaging\Lib\net40
# this is where we are merging the two or more dll in one single dll or binary
# /out: for output dll name along with relative path
# /t: for library or exe
# /log: for text log
# /V4 specify the dlls.....
iLMerge.exe /out:./Lib/net40/AllinOneMergedDll.dll /t:library /log:MergeLog.txt
/V4 C:\testproject1\bin\Debug\testproject1.dll C:\testproject1\bin\Debug\testproject2.dll
C:\testproject1\bin\Debug\testproject3.dll
cd ..
@ Echo off
# finally we are going to reset environment variable path back to its original value
set PATH=%oldPath%