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Instead of trying to juggle conditional traps, it's far simpler to exit conditionally or send a signal when commands or command groups fail. set -Eeuo pipefail shopt -s lastpipe # Allow a subs...
#2: Post edited
by
r~~
·
2025-10-30T20:22:29Z (11 months ago)
- Instead of trying to juggle conditional traps, it's far simpler to exit conditionally or send a signal when commands or command groups fail.
- ```
- set -Eeuo pipefail
- shopt -s lastpipe
- # Allow a subshell to signal the parent process for a fatal error.
- trap 'exit 2' USR1
- if test -z "$*"; then
- grep foo
- # grep's exit codes are assumed to be compatible with the wrapper's.
- else
- { find "$@" -type f || kill -USR1 "$$"; } \
- | xargs grep foo || exit 1
# Since the xargs grep is not in a subshell, we can exit 1 directly from it# without needing a second signal.- fi
- ```
- (Side note: you don't; need; to go nuts; with semicolons! They are equivalent to line terminators, so they're never necessary at the end of a line or a trap handler.)
- Instead of trying to juggle conditional traps, it's far simpler to exit conditionally or send a signal when commands or command groups fail.
- ```
- set -Eeuo pipefail
- shopt -s lastpipe
- # Allow a subshell to signal the parent process for a fatal error.
- trap 'exit 2' USR1
- if test -z "$*"; then
- grep foo
- # grep's exit codes are assumed to be compatible with the wrapper's.
- else
- { find "$@" -type f || kill -USR1 "$$"; } \
- | xargs grep foo || exit 1
- fi
- ```
- (Side note: you don't; need; to go nuts; with semicolons! They are equivalent to line terminators, so they're never necessary at the end of a line or a trap handler.)
#1: Initial revision
by
r~~
·
2025-10-30T20:20:57Z (11 months ago)
Instead of trying to juggle conditional traps, it's far simpler to exit conditionally or send a signal when commands or command groups fail.
```
set -Eeuo pipefail
shopt -s lastpipe
# Allow a subshell to signal the parent process for a fatal error.
trap 'exit 2' USR1
if test -z "$*"; then
grep foo
# grep's exit codes are assumed to be compatible with the wrapper's.
else
{ find "$@" -type f || kill -USR1 "$$"; } \
| xargs grep foo || exit 1
# Since the xargs grep is not in a subshell, we can exit 1 directly from it
# without needing a second signal.
fi
```
(Side note: you don't; need; to go nuts; with semicolons! They are equivalent to line terminators, so they're never necessary at the end of a line or a trap handler.)