'times' should be a special builtin

[stephane-chazelas]

In ksh93, times is implemented as an alias to "{ { time;} 2>&1;}" and "command" as an alias to "command " (which means aliases are expanded after it).

That means that things like:

$ ksh93 -c 'LC_ALL=C times'
ksh93: syntax error at line 1: `{' unexpected
$ ksh93 -c 'command times'
ksh93: syntax error at line 1: `{' unexpected

Don't work, so the times utility is not POSIX compliant.

"times" should be implemented as a special builtin.

More generally, even though allowed by POSIX, implementing builtin utilities as aliases is not a good idea IMO if only for the reasons detailed at:
http://thread.gmane.org/gmane.comp.standards.posix.austin.general/12485/focus=12568

[McDutchie]

As Stéphane has pointed out on austin-group-l, the output of times (being actually the output of time) on ksh93 is not POSIX compliant either. It should follow this format. So that's another reason to implement a proper special builtin.

[krader1961]

I'm laughing out loud (LOL!) because so many responses to my proposed changes have stated that adherence to POSIX is paramount. Yet the old ksh development team couldn't be bothered to spend what should take no more than a day (total time for all involved) to implement a POSIX compliant times command. This came to my attention due to PR #1327 and PR #1329. At first glance it looks like the path through sh_exec() that used the uninitialized var tb exists solely to allow the times alias to work. As well as produce output reflecting zero CPU time used when no pipeline follows the time keyword. The latter case being an error that should behave as an error; e.g., a non-zero status and an error message written to stderr rather than meaningless times written to stdout.