When Bash is interactive, in the absence of any traps, it ignores
SIGTERM (so that ‘
kill 0’ does not kill an interactive shell),
is caught and handled (so that the
wait builtin is interruptible).
When Bash receives a
SIGINT, it breaks out of any executing loops.
In all cases, Bash ignores
If job control is in effect (see Job Control), Bash
Non-builtin commands started by Bash have signal handlers set to the
values inherited by the shell from its parent.
When job control is not in effect, asynchronous commands
SIGQUIT in addition to these inherited
Commands run as a result of
command substitution ignore the keyboard-generated job control signals
The shell exits by default upon receipt of a
Before exiting, an interactive shell resends the
all jobs, running or stopped.
Stopped jobs are sent
SIGCONT to ensure that they receive
To prevent the shell from sending the
SIGHUP signal to a
particular job, it should be removed
from the jobs table with the
builtin (see Job Control Builtins) or marked
to not receive
huponexit shell option has been set with
(see The Shopt Builtin), Bash sends a
SIGHUP to all jobs when
an interactive login shell exits.
If Bash is waiting for a command to complete and receives a signal
for which a trap has been set, the trap will not be executed until
the command completes.
When Bash is waiting for an asynchronous
command via the
wait builtin, the reception of a signal for
which a trap has been set will cause the
wait builtin to return
immediately with an exit status greater than 128, immediately after
which the trap is executed.