wordexp is unsupported

[ddevault]

See the following POSIX pages:

​https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wordexp.h.html

​https://pubs.opengroup.org/onlinepubs/9699919799/functions/wordexp.html

[davidkaroly]

This should be easily adaptable from MUSL, see: ​https://git.musl-libc.org/cgit/musl/tree/src/misc/wordexp.c

However... MUSL wordexp implementation uses pipe2 which is non-POSIX (but it's there in most actual implementations like Linux, FreeBSD, Illumos, MUSL)

So if we want to be really careful then we should implement _pipe2() in libroot and use that from wordexp. Then we can export pipe2() from libbsd. Or just make a shortcut and define pipe2() in libroot - the question is: do we think there might be open source POSIX software that wants to redefine pipe2.

[waddlesplash]

It's worth noting that OpenBSD does not support wordexp at all (probably because there is no "safe" way to implement it; note the musl implementation invokes /bin/sh!) So I'm not entirely sure we should support it either.

[davidkaroly]

yes the backtick handling in musl is not so nice

eh forget about my previous comment that was completely off the mark.

MUSL does the same thing as FreeBSD, NetBSD, DragonflyBSD which is doing the whole thing with sh - so you're right, this does not look like a good way forward.

This leaves us with either the current situation (no wordexp) or adapt from glibc which does seem to have a more proper implementation. (calling out to shell only for the backticks and dollar-parentheses)