/target:library
The /target:library option causes the compiler to create a DLL rather than an executable file (EXE). The DLL will be created with the .dll extension.
Unless otherwise specified with the /out option, the output file name takes the name of the first input file.
When specified at the command line, all files up to the next /out, /target:winexe, or /target:exe option are used to create the .dll.
When building a .dll, a Main method is not required.
Compile in.cs
, creating in.dll
:
csc /target:library in.cs