In windows bat file, %0, %1,…, %9 are the first, second, …, tenth parameter of the command line. The first parameter is the command itself. Suppose the bat file is test.bat that has the following command:
The command line: test.bat will output test.bat. The command line: .\test.bat will output .\test.bat. The command line: “test.bat” will output “test.bat”. The command line:”.\test.bat” will output “.\test.bat”.
~ before the digit will do something extra to the parameter. %~0 will remove the quote marks of the first parameter if it has any. So, “test.bat” will output test.bat, “.\test.bat” will output .\test.bat.
~f will expand the parameter to the full path name. So %~f0 may expand to C:\dir\test.bat.
~d will extract the disk part of the parameter. So test.bat may output C:
~p will extract the path part of the parameter. So test.bat may output \dir\
~dp will extract both the disk part and the path part of the parameter. So %~dp0 may expand to C:\dir\. Note that even the command in the command line does not include drive or path, %~dp0 still expands to the drive and path, i.e., the command is first expanded to the full path name then the drive and path are extracted. Things get weird for %~dp1, %~dp2,…, if you provide a non-existed file. If the non-existence file is of the form of an absolute path, the result is the drive and path part of the file. If the non-existence file has a relative path, the relative path would be prefixed the drive/path of the script.