The %c
is the single character format specifier for wsprintf
.
The code is used to generate path names of this form:
\\.\C:
This is the path to a physical volume. You use such a path when performing file operations directly on a volume, bypassing the file system. So you'd use such a path when implementing raw disk copy, for example. The documentation for CreateFile
has more detail.
This all ties in with the fact that the code you found this in performs a raw disk copy.