hush: add support for "set -o pipefail"

function                                             old     new   delta
checkjobs                                            467     517     +50
builtin_set                                          259     286     +27
o_opt_strings                                          -      10     +10
hush_main                                           1011    1013      +2
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/0 up/down: 89/0)               Total: 89 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/shell/hush_test/hush-misc/pipefail.tests b/shell/hush_test/hush-misc/pipefail.tests
new file mode 100755
index 0000000..9df8418
--- /dev/null
+++ b/shell/hush_test/hush-misc/pipefail.tests
@@ -0,0 +1,45 @@
+echo Default:
+echo "true | true:"
+  true | true; echo $?
+! true | true; echo $?
+echo "true | false:"
+  true | false; echo $?
+! true | false; echo $?
+echo "false | true:"
+  false | true; echo $?
+! false | true; echo $?
+echo "exit 2 | exit 3 | exit 4:"
+  exit 2 | exit 3 | exit 4; echo $?
+! exit 2 | exit 3 | exit 4; echo $?
+
+echo Pipefail on:
+set -o pipefail
+echo "true | true:"
+  true | true; echo $?
+! true | true; echo $?
+echo "true | false:"
+  true | false; echo $?
+! true | false; echo $?
+echo "false | true:"
+  false | true; echo $?
+! false | true; echo $?
+echo "exit 2 | exit 3 | exit 4:"
+  exit 2 | exit 3 | exit 4; echo $?
+! exit 2 | exit 3 | exit 4; echo $?
+
+echo Pipefail off:
+set +o pipefail
+echo "true | true:"
+  true | true; echo $?
+! true | true; echo $?
+echo "true | false:"
+  true | false; echo $?
+! true | false; echo $?
+echo "false | true:"
+  false | true; echo $?
+! false | true; echo $?
+echo "exit 2 | exit 3 | exit 4:"
+  exit 2 | exit 3 | exit 4; echo $?
+! exit 2 | exit 3 | exit 4; echo $?
+
+echo Done