diff options
Diffstat (limited to 'shell/ash_test/ash-signals')
-rw-r--r-- | shell/ash_test/ash-signals/sigint1.right | 1 | ||||
-rwxr-xr-x | shell/ash_test/ash-signals/sigint1.tests | 41 |
2 files changed, 42 insertions, 0 deletions
diff --git a/shell/ash_test/ash-signals/sigint1.right b/shell/ash_test/ash-signals/sigint1.right new file mode 100644 index 000000000..a9094b056 --- /dev/null +++ b/shell/ash_test/ash-signals/sigint1.right @@ -0,0 +1 @@ +Sending SIGINT to main shell PID diff --git a/shell/ash_test/ash-signals/sigint1.tests b/shell/ash_test/ash-signals/sigint1.tests new file mode 100755 index 000000000..20e45d940 --- /dev/null +++ b/shell/ash_test/ash-signals/sigint1.tests @@ -0,0 +1,41 @@ +# What should happen if non-interactive shell gets SIGINT? + +(sleep 1; echo Sending SIGINT to main shell PID; exec kill -INT $$) & + +# We create a child which exits with 0 even on SIGINT +# (This is truly necessary only if SIGINT is generated by ^C, +# in this testcase even bare "sleep 2" would do because +# we don't send SIGINT _to_ the_ child_...) +$THIS_SH -c 'trap "exit 0" SIGINT; sleep 2' + +# In one second, we (main shell) get SIGINT here. +# The question is whether we should, or should not, exit. + +# bash will not stop here. It will execute next command(s). + +# The rationale for this is described here: +# http://www.cons.org/cracauer/sigint.html +# +# Basically, bash will not exit on SIGINT immediately if it waits +# for a child. It will wait for the child to exit. +# If child exits NOT by dying on SIGINT, then bash will not exit. +# +# The idea is that the following script: +# | emacs file.txt +# | more cmds +# User may use ^C to interrupt editor's ops like search. But then +# emacs exits normally. User expects that script doesn't stop. +# +# This is a nice idea, but detecting "did process really exit +# with SIGINT?" is racy. Consider: +# | bash -c 'while true; do /bin/true; done' +# When ^C is pressed while bash waits for /bin/true to exit, +# it may happen that /bin/true exits with exitcode 0 before +# ^C is delivered to it as SIGINT. bash will see SIGINT, then +# it will see that child exited with 0, and bash will NOT EXIT. + +# Therefore we do not implement bash behavior. +# I'd say that emacs need to put itself into a separate pgrp +# to isolate shell from getting stray SIGINTs from ^C. + +echo Next command after SIGINT was executed |