bash: improve prior_trap processing#5142
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mitchellh merged 1 commit intoghostty-org:mainfrom Jan 16, 2025
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We use `trap` to bootstrap our installation function (__bp_install). We
remove our code upon first execution but need to restore any preexisting
trap calls. We previously used `sed` to process the trap string, but
that had two downsides:
1. `sed` is an external command dependency. It needs to exist on the
system, and we need to invoke it in a subshell (which has some
runtime cost).
2. The regular expression pattern was imperfect and didn't handle
trickier cases like `'` characters in the trap string:
$ (trap "echo 'hello'" DEBUG; trap -p DEBUG)
hello
trap -- 'echo '\''hello'\''' DEBUG
This change removes the dependency on `sed` by locally evaluating the
trap string and extracting any prior trap. This works reliably because
we control the format our trap string, which looks like this (with
newlines expanded):
__bp_trap_string="$(trap -p DEBUG)"
trap - DEBUG
__bp_install
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We use
trapto bootstrap our installation function (__bp_install). We remove our code upon first execution but need to restore any preexisting trap calls. We previously usedsedto process the trap string, but that had two downsides:sedis an external command dependency. It needs to exist on the system, and we need to invoke it in a subshell (which has some runtime cost).The regular expression pattern was imperfect and didn't handle trickier cases like
'characters in the trap string:This change removes the dependency on
sedby locally evaluating the trap string and extracting any prior trap. This works reliably because we control the format our trap string, which looks like this (with newlines expanded):Upstream: rcaloras/bash-preexec#170