On Fri, Mar 26, 2010 at 2:40 AM, Eric Blake <ebl...@redhat.com> wrote: > Yes. POSIX requires this for non-interactive shells, and does not > forbid it for interactive shells. Technically, this code could be > modified to exempt interactive shells from hard-ignores, or left as is > by treating both classes of shells identically in keeping things > hard-ignored; either approach still meets POSIX. >
The code does explicitly hard ignore signals ignored when entering a non-interactive shell; see initialize_terminating_signals() in sig.c. The problem is that in addition to this, it ends up doing a hard ignore for the special signals in GETORIGSIG() -- not for all terminating signals, just the special signals. I know POSIX does not say anything about it, but neither does the man page. The result of this is confusing behaviour. It should either hard ignore _all_ signals or none. I really don't see any reason for a hard ignore for special signals via GETORIGSIG when we already have the stuff in place in initialize_terminating_signals() that does the right thing. What's more, BeOS gets special treatment in all this; its hard ignore flag is removed after GETORIGSIG() for SIGINT because BeOS sets SIGINT to SIG_IGN by default: #if defined (__BEOS__) /* BeOS sets SIGINT to SIG_IGN! */ original_signals[SIGINT] = SIG_DFL; sigmodes[SIGINT] &= ~SIG_HARD_IGNORE; #endif -- Siddhesh Poyarekar http://siddhesh.in
