timeout: --foreground, --preserve-status, and --signal.

--signal is simply a synonym for the exiting -s.

--foreground disables functionality we didn't yet have: putting the
child into a new process group. I've added the functionality and the
flag to disable it.

--preserve-status also makes it clear that our exit statuses didn't match
the coreutils version. In addition to callers that use --preserve-status
to get away from this madness, I also have callers that check for
specific exit values. This patch implements --preserve-status but also
fixes all the other exit statuses.

(The "125" exit value is broken for toybox in the same way that
`toybox grep --whoops ; echo $?` is. To fix this, we'd need some way to
signal that command-line parsing failures should exit with a different
value than the usual 1 --- 2 for grep, 125 for timeout. I've done as much
as grep manages, and left a TODO.)

Also add timeout tests. I couldn't think of an easy test for
--foreground, so I tested that manually with strace.

Also add some newlines to the `toybox --help` output to make it easier
to find the different sections, and expand the section on durations to
call out that fractions are supported as a matter of policy.

As long as timeout and sleep have text describing the duration syntax,
make them the same. (Personally I'd remove both in favor of the `toybox
--help` output, but as long as they're duplicated, keep them consistent.)

Also remove the SLEEP_FLOAT variant --- xparsetime means that sleep no
longer requires floating point to support sub-second resolution.

1 files changed, 7 insertions, 4 deletions

diff --git a/Config.in b/Config.in
index 2136dae8..16a04f90 100644
--- a/Config.in
+++ b/Config.in
@@ -28,11 +28,14 @@ config TOYBOX
 	  --help		Show command help (only)
 	  --version	Show toybox version (only)
 
-	  The filename "-" means stdin/stdout, "--" stops argument parsing,
-	  and numerical arguments accept a single letter suffix for
+	  The filename "-" means stdin/stdout, and "--" stops argument parsing.
+
+	  Numerical arguments accept a single letter suffix for
 	  kilo, mega, giga, tera, peta, and exabytes, plus an additional
-	  "d" to indicate decimal 1000's instead of 1024. Durations take
-          minute, hour, or day suffixes (ala 0.1m = 6s).
+	  "d" to indicate decimal 1000's instead of 1024.
+
+	  Durations can be decimal fractions and accept minute ("m"), hour ("h"),
+	  or day ("d") suffixes (so 0.1m = 6s).
 
 config TOYBOX_SUID
 	bool "SUID support"