Improve signal name<->number conversions.

Include all the signals, not just the POSIX ones.

In particular, improve support for real-time signals. My attempt to
switch AOSP builds over to toybox timeout got reverted when I broke the
ART build bots which use SIGRTMIN+2.

Also fix `kill -l 3` to show "QUIT" and `kill -l QUIT` to show "3".

Also make the `kill -l` output include numbers and names, and format it
to look better on a 80x24 tty, because it's always August 1978 somewhere.

1 files changed, 3 insertions, 2 deletions

diff --git a/toys/posix/kill.c b/toys/posix/kill.c
index f8e86b67..ee68980b 100644
--- a/toys/posix/kill.c
+++ b/toys/posix/kill.c
@@ -67,8 +67,9 @@ void kill_main(void)
       char *s = NULL;
 
       if (signum>=0) s = num_to_sig(signum&127);
-      puts(s ? s : "UNKNOWN");
-    } else sig_to_num(NULL);
+      if (isdigit(**args)) puts(s ? s : "UNKNOWN");
+      else printf("%d\n", signum);
+    } else list_signals();
     return;
   }