Implement time

[GrayJack]

This is a tracking issue for the time utility.

Required options and flags in the POSIX standard:

• [X] p (long: posix, alias: portability)

Required extension options and flags:

• [ ] l (long: rusage)
• [ ] o (long: output)
• [ ] a (long: append, requires: o)

Notes: ¹ : Long name not defined on other implementation of this utility. Implementer must choose a long name. ² : Short name (one letter) not defined on other implementation of this utility. Implementer must choose. a short name

References

POSIX standard text FreeBSD Manual NetBSD Manual OpenBSD Manual DragonFlyBSD Manual

Unresolved questions:

Each time implementation has some unique extensions. One may need one of those in their respective system.

History

p flag/option implemented in #141

[envp]

Posting TODO here from #141:

Compatibility so far for time.1:

• [x] POSIX.2
• [x] MacOS
• [x] Linux WITHOUT GNU extensions
• [x] Linux GNU extensions
• [x] FreeBSD
• [x] NetBSD
• [x] OpenBSD
• [x] DragonflyBSD
• [x] Illumos
• [x] Solaris
• [x] Fuchsia: No getrusage syscall

[envp]

#144 adds features from BSD time commands. -l is still unimplemented, as that requires some more work on macos (discussed on the PR)