sleep: Overhaul.

[des]

Summary

Program:

• Add a dummy getopt(3) loop to handle --.
• Move interval parsing out into a separate function.
• Print a diagnostic for every invalid interval.
• Check for NaN and infinity.
• Improve bounds checks.

Manual page:

• Miscellaneous markup fixes.
• Reword DESCRIPTION section.
• Move text about GNU compatibility to STANDARDS section.
• Convert examples from csh to sh.

Sponsored by: Klara, Inc.

[des]

add <unistd.h> for getopt()

[bcr]

OK from manpages.

[des]

tweak example

[des]

simplify overflow check

[des]

just remembered that we need to test for equality after casting

[des]

print tv_sec as long rather than int

[des]

typo

[des]

smallest value representable by struct timespec

[des]

remove obsolete comment, use exit instead of return