Use sed in a more POSIX compliant way

[mkrzewic]

Fixes #112

[mpatrascoiu]

Thanks! I don't see the need for gcc --> cc change.

Davix is officially supported on gcc. By changing it to cc, I don't want to raise hopes for other non-gcc compilers. Those are simply untested by us.

[mkrzewic]

removed the gcc->cc thing. it does seem to work fine with llvm though :)

[mkrzewic]

the problem I'm trying to solve is building as an automatic dependency of root on FreeBSD. gcc is not always there (can be installed, but it is a rather large dependency), llvm is the default. Davix and the rest can be built via the ports tree where these issues can be patched, but it would be nice if root could be built from source with as little effort as possible, just relying on roots own build system.

[mpatrascoiu]

Hello,

Yes, but we shouldn't change things in Davix to non-supported configurations just for the purpose of having Root build 🙂
I'm merging the sed change.

Thanks!

[hahnjo]

Note that this PR is not fully correct since POSIX sed doesn't actually have any switch for in-place edits. The problem comes from how GNU sed and BSD sed accept different arguments for their respective -i switches. In fact, I think this PR breaks the script with GNU sed, see this reproducer:

$ sed -i "" "s/a/b/g" test.txt 
sed: can't read s/a/b/g: No such file or directory

The correct incarnation would be sed -i"" "s/a/b/g" test.txt, but I think that doesn't work on BSD sed... From what I remember, there actually is no invocation that works for both implementation (or it is so obscure that I didn't find it back then).

More generally, the script talks about SLC6 and CC7 which are both EOL. Is it maybe time to just remove this script?