We now accept symbolic and numeric mode strings using the
--mode or -m option for install. This is used either when
moving files into a directory, or when creating component
directories with the -d option. This feature was designed
to mirror the GNU implementation, including the possibly
quirky behaviour of `install --mode=u+wx file dir`
resulting in dir/file having exactly permissions 0300.
Extensive integration tests are included.
This chnage required a higher libc dependency.
Add install utility skeleton source, based on
mv, including the getopts setup mirroring
GNU's `man install` documentation. Also
add a single test and build system code.
The main motivation is to move toward running those tests for a specific
target, that is, if a test won't run on Windows, then we shouldn't build
it. This was previously the default behavior and prevented a successful
run on AppVeyor.
I borrowed this pattern from the tests in the Cargo project.
