Updating gnulib has caused -Wformat-signedness to be enabled. This
has revealed many problems in C format strings. The fixes here fall
into the following main categories:
- Using %d with an unsigned parameter.
- %x and %o expect an unsigned argument.
- uid_t and gid_t are unsigned on Linux. The safe way to print these
is to cast them to uintmax_t and then print them using the %ju
modifier (see http://stackoverflow.com/a/1401581).
- Using %d to print an enum. Since enums may be either char or int,
I fixed this by casting the enum to int.
- strtol_error & lzma_ret are both unsigned types.
chmod: Disallow negative mode, document mode affected by umask.
mkdir-mode: Disallow negative mode, document that filesystems
may interpret the mode in different ways.
mknod: Disallow negative mode, document mode affected by umask.
umask: Check the range of umask mask value carefully.
These commands are used to create block and char device
nodes or FIFOs (named pipes) in the filesystem.
The umask command is required also because the permissions
used by mknod are masked by the umask.
Also document and guarantee that the umask starts as 022.
