Correct detecting the right sdphost binary for linux

[jepler]

On my Linux system, "uname -i" just prints "unknown". "uname -m" prints "x86_64".

[ladyada]

i think its ok but will also wait for thach to reply!

[hathach]

It is odd, on my machine, both -i and -m has the same value x86_64. Accept for ?= false. I think it is good to merge

[hathach]

perfect now

[jepler]

I researched the "why" a bit and found:

POSIX doesn't define -p or -i. In GNU coreutils they are marked as non-portable, as you indicate; the default implementation relies on two optional operating system features, the three-argument form of sysinfo(2) (from SunOS) and the six-argument form of sysctl(3) (from the BSDs; neither of which are available on Linux).

Thus on Debian and derived distributions (apart from Ubuntu and its derivatives), you simply get unknown.

On Fedora and related distributions, uname is patched to return the machine type (-m) as processor (-p) and hardware platform (-i), with the latter tweaked to produce i386 for any value of the form i?86.

On Ubuntu and derivatives, a variant of the Fedora patch is used, which additionally checks for AMD CPUs on i686 processors and produces athlon instead.

https://unix.stackexchange.com/questions/307955/uname-p-i-are-unknown

[hathach]

Thanks @jepler it is good reading 👍 👍