en Copyright 2015 Java http://172.16.0.5:8080/history/freebsd-12.1/bin/sh/tests/execution/pipefail7.0#3abaec56 MFC r344502: sh: Add set -o pipefailThe pipefail option allows checking the exit status of all commands in apipeline more easily, at a limited cost of complexity in sh itself. It workssimilarly to the option in bash, ksh93 and mksh.Like ksh93 and unlike bash and mksh, the state of the option is saved when apipeline is started. Therefore, even in the case of commands like A | B &a later change of the option does not affect the exit status, the same way (A | B) &works.Since SIGPIPE is not handled specially, more work in the script is requiredfor a proper exit status for pipelines containing commands such as head thatmay terminate successfully without reading all input. This can be somethinglike( cmd1 r=$? if [ "$r" -gt 128 ] && [ "$(kill -l "$r")" = PIPE ]; then exit 0 else exit "$r" fi) | headPR: 244270Relnotes: yes List of files: /freebsd-12.1/bin/sh/tests/execution/pipefail7.0 Sun, 24 Mar 2019 22:10:26 +0000 Jilles Tjoelker <jilles@FreeBSD.org>