1	# Cases relevant to Oil:
2	#
3	# - shopt -s command_sub_errexit
4	# - and maybe inherit_errexit and strict_errexit (OSH)
5	#
6	# Summary:
7	# - errexit is reset to false in ash/bash -- completely ignored!
8	# - local assignment is different than global! The exit code and errexit
9	# behavior are different because the concept of the "last command" is
10	# different.
11	# - ash has copied bash behavior!
12
13	#### command sub: errexit is NOT inherited and outer shell keeps going
14
15	# This is the bash-specific bug here:
16	# https://blogs.janestreet.com/when-bash-scripts-bite/
17	# See inherit_errexit below.
18	#
19	# I remember finding a script that relies on bash's bad behavior, so OSH copies
20	# it. Instead command_sub_errexit, is recommended.
21
22	set -o errexit
23	echo $(echo one; false; echo two) # bash/ash keep going
24	echo parent status=$?
25	## STDOUT:
26	one two
27	parent status=0
28	## END
29	# dash and mksh: inner shell aborts, but outer one keeps going!
30	## OK dash/mksh STDOUT:
31	one
32	parent status=0
33	## END
34
35	#### command sub with inherit_errexit only
36	set -o errexit
37	shopt -s inherit_errexit || true
38	echo zero
39	echo $(echo one; false; echo two) # bash/ash keep going
40	echo parent status=$?
41	## STDOUT:
42	zero
43	one
44	parent status=0
45	## END
46	## N-I ash STDOUT:
47	zero
48	one two
49	parent status=0
50	## END
51
52	#### strict_errexit with command sub stops program
53	set -o errexit
54	shopt -s inherit_errexit || true
55	shopt -s strict_errexit || true
56	if echo $(echo 1; false; echo 2); then
57	echo A
58	fi
59	echo done
60
61	## status: 1
62	## stdout-json: ""
63
64	## N-I bash/ash status: 0
65	## N-I bash/ash STDOUT:
66	1 2
67	A
68	done
69	## END
70
71	## N-I dash/mksh status: 0
72	## N-I dash/mksh STDOUT:
73	1
74	A
75	done
76	## END
77
78	#### {inherit,strict}_errexit: command sub with a single command
79	set -o errexit
80	shopt -s inherit_errexit || true
81	shopt -s strict_errexit || true
82	if echo $(false); then
83	echo A
84	fi
85	echo done
86	## status: 1
87	## stdout-json: ""
88
89	## N-I dash/bash/mksh/ash status: 0
90	## N-I dash/bash/mksh/ash STDOUT:
91
92	A
93	done
94	## END
95
96	#### strict_errexit with command sub in weird place
97	shopt -s oil:basic
98
99	if echo 1 > $(echo tmp); then
100	echo 2
101	fi
102	## status: 1
103	## STDOUT:
104	## END
105	## N-I dash/bash/mksh/ash status: 0
106	## N-I dash/bash/mksh/ash STDOUT:
107	2
108	## END
109
110	#### strict_errexit allows pipeline because you can set -o pipefail
111	case $SH in (dash|ash) exit ;; esac
112
113	set -o errexit
114	set -o pipefail
115	shopt -s strict_errexit || true
116
117	if echo 1 | grep 1; then
118	echo one
119	fi
120
121	#{ echo 3; exit 3; } | grep 3
122	#echo status ${PIPESTATUS[@]}
123
124	if { echo 5; exit 5; } | grep 5; then
125	echo 'should not succeed'
126	else
127	echo status ${PIPESTATUS[@]}
128	fi
129	## STDOUT:
130	1
131	one
132	5
133	status 5 0
134	## END
135	## N-I dash/ash stdout-json: ""
136
137	#### command sub with command_sub_errexit only
138	set -o errexit
139	shopt -s command_sub_errexit || true
140	echo zero
141	echo $(echo one; false; echo two) # bash/ash keep going
142	echo parent status=$?
143	## STDOUT:
144	zero
145	one two
146	parent status=0
147	## END
148	## N-I dash/mksh STDOUT:
149	zero
150	one
151	parent status=0
152	## END
153
154	#### command sub with inherit_errexit and command_sub_errexit
155	set -o errexit
156
157	# bash implements inherit_errexit, but it's not as strict as OSH.
158	shopt -s inherit_errexit || true
159	shopt -s command_sub_errexit || true
160	echo zero
161	echo $(echo one; false; echo two) # bash/ash keep going
162	echo parent status=$?
163	## STDOUT:
164	zero
165	## END
166	## status: 1
167	## N-I dash/mksh/bash status: 0
168	## N-I dash/mksh/bash STDOUT:
169	zero
170	one
171	parent status=0
172	## END
173	## N-I ash status: 0
174	## N-I ash STDOUT:
175	zero
176	one two
177	parent status=0
178	## END
179
180	#### command sub: last command fails but keeps going and exit code is 0
181	set -o errexit
182	echo $(echo one; false) # we lost the exit code
183	echo status=$?
184	## STDOUT:
185	one
186	status=0
187	## END
188
189	#### global assignment with command sub: middle command fails
190	set -o errexit
191	s=$(echo one; false; echo two;)
192	echo "$s"
193	## status: 0
194	## STDOUT:
195	one
196	two
197	## END
198	# dash and mksh: whole thing aborts!
199	## OK dash/mksh stdout-json: ""
200	## OK dash/mksh status: 1
201
202	#### global assignment with command sub: last command fails and it aborts
203	set -o errexit
204	s=$(echo one; false)
205	echo status=$?
206	## stdout-json: ""
207	## status: 1
208
209	#### local: middle command fails and keeps going
210	set -o errexit
211	f() {
212	echo good
213	local x=$(echo one; false; echo two)
214	echo status=$?
215	echo $x
216	}
217	f
218	## STDOUT:
219	good
220	status=0
221	one two
222	## END
223	# for dash and mksh, the INNER shell aborts, but the outer one keeps going!
224	## OK dash/mksh STDOUT:
225	good
226	status=0
227	one
228	## END
229
230	#### local: last command fails and also keeps going
231	set -o errexit
232	f() {
233	echo good
234	local x=$(echo one; false)
235	echo status=$?
236	echo $x
237	}
238	f
239	## STDOUT:
240	good
241	status=0
242	one
243	## END
244
245	#### local and inherit_errexit / command_sub_errexit
246	# I've run into this problem a lot.
247	set -o errexit
248	shopt -s inherit_errexit || true # bash option
249	shopt -s command_sub_errexit || true # oil option
250	f() {
251	echo good
252	local x=$(echo one; false; echo two)
253	echo status=$?
254	echo $x
255	}
256	f
257	## status: 1
258	## STDOUT:
259	good
260	## END
261	## N-I ash status: 0
262	## N-I ash STDOUT:
263	good
264	status=0
265	one two
266	## END
267	## N-I bash/dash/mksh status: 0
268	## N-I bash/dash/mksh STDOUT:
269	good
270	status=0
271	one
272	## END
273
274	#### global assignment when last status is failure
275	# this is a bug I introduced
276	set -o errexit
277	[ -n "${BUILDDIR+x}" ] && _BUILDDIR=$BUILDDIR
278	BUILDDIR=${_BUILDDIR-$BUILDDIR}
279	echo status=$?
280	## STDOUT:
281	status=0
282	## END
283
284	#### global assignment when last status is failure
285	# this is a bug I introduced
286	set -o errexit
287	x=$(false) || true # from abuild
288	[ -n "$APORTSDIR" ] && true
289	BUILDDIR=${_BUILDDIR-$BUILDDIR}
290	echo status=$?
291	## STDOUT:
292	status=0
293	## END
294
295	#### strict_errexit prevents errexit from being disabled in function
296	set -o errexit
297	fun() { echo fun; }
298
299	fun || true # this is OK
300
301	shopt -s strict_errexit || true
302
303	echo 'builtin ok' || true
304	env echo 'external ok' || true
305
306	fun || true # this fails
307
308	## status: 1
309	## STDOUT:
310	fun
311	builtin ok
312	external ok
313	## END
314	## N-I dash/bash/mksh/ash status: 0
315	## N-I dash/bash/mksh/ash STDOUT:
316	fun
317	builtin ok
318	external ok
319	fun
320	## END
321
322	#### strict_errexit prevents errexit from being disabled in brace group
323	set -o errexit
324	# false failure is NOT respected either way
325	{ echo foo; false; echo bar; } || echo "failed"
326
327	shopt -s strict_errexit || true
328	{ echo foo; false; echo bar; } || echo "failed"
329	## status: 1
330	## STDOUT:
331	foo
332	bar
333	## END
334
335	## N-I dash/bash/mksh/ash status: 0
336	## N-I dash/bash/mksh/ash STDOUT:
337	foo
338	bar
339	foo
340	bar
341	## END
342
343	#### strict_errexit prevents errexit from being disabled in subshell
344	set -o errexit
345	shopt -s inherit_errexit || true
346
347	# false failure is NOT respected either way
348	( echo foo; false; echo bar; ) || echo "failed"
349
350	shopt -s strict_errexit || true
351	( echo foo; false; echo bar; ) || echo "failed"
352	## status: 1
353	## STDOUT:
354	foo
355	bar
356	## END
357
358	## N-I dash/bash/mksh/ash status: 0
359	## N-I dash/bash/mksh/ash STDOUT:
360	foo
361	bar
362	foo
363	bar
364	## END
365
366	#### strict_errexit and ! && || if while until
367	prelude='set -o errexit
368	shopt -s strict_errexit || true
369	fun() { echo fun; }'
370
371	$SH -c "$prelude; ! fun; echo 'should not get here'"
372	echo bang=$?
373	echo --
374
375	$SH -c "$prelude; fun || true"
376	echo or=$?
377	echo --
378
379	$SH -c "$prelude; fun && true"
380	echo and=$?
381	echo --
382
383	$SH -c "$prelude; if fun; then true; fi"
384	echo if=$?
385	echo --
386
387	$SH -c "$prelude; while fun; do echo while; exit; done"
388	echo while=$?
389	echo --
390
391	$SH -c "$prelude; until fun; do echo until; exit; done"
392	echo until=$?
393	echo --
394
395
396	## STDOUT:
397	bang=1
398	--
399	or=1
400	--
401	and=1
402	--
403	if=1
404	--
405	while=1
406	--
407	until=1
408	--
409	## END
410	## N-I dash/bash/mksh/ash STDOUT:
411	fun
412	should not get here
413	bang=0
414	--
415	fun
416	or=0
417	--
418	fun
419	and=0
420	--
421	fun
422	if=0
423	--
424	fun
425	while
426	while=0
427	--
428	fun
429	until=0
430	--
431	## END
432
433	#### if pipeline doesn't fail fatally
434	set -o errexit
435	set -o pipefail
436
437	f() {
438	local dir=$1
439	if ls $dir | grep ''; then
440	echo foo
441	echo ${PIPESTATUS[@]}
442	fi
443	}
444	rmdir $TMP/_tmp || true
445	rm -f $TMP/*
446	f $TMP
447	f /nonexistent # should fail
448	echo done
449
450	## N-I dash status: 2
451	## N-I dash stdout-json: ""
452	## STDOUT:
453	done
454	## END
455
456	#### errexit is silent (verbose_errexit for Oil)
457	shopt -u verbose_errexit 2>/dev/null || true
458	set -e
459	false
460	## stderr-json: ""
461	## status: 1
462
463	#### command sub errexit preserves exit code
464	set -e
465	shopt -s command_sub_errexit || true
466
467	echo before
468	echo $(exit 42)
469	echo after
470	## STDOUT:
471	before
472	## END
473	## status: 42
474	## N-I dash/bash/mksh/ash STDOUT:
475	before
476
477	after
478	## N-I dash/bash/mksh/ash status: 0
479
480	#### strict_errexit without errexit
481	myproc() {
482	echo myproc
483	}
484	myproc || true
485
486	# This should be a no-op I guess
487	shopt -s strict_errexit || true
488	myproc || true
489
490	## STDOUT:
491	myproc
492	myproc
493	## END
494
495
496	#### What's in strict:all?
497
498	# inherit_errexit, strict_errexit, but not command_sub_errexit!
499	# for that you need oil:basic!
500
501	set -o errexit
502	shopt -s strict:all || true
503
504	# inherit_errexit is bash compatible, so we have it
505	#echo $(date %x)
506
507	# command_sub_errexit would hide errors!
508	f() {
509	local d=$(date %x)
510	}
511	f
512
513	deploy_func() {
514	echo one
515	false
516	echo two
517	}
518
519	if ! deploy_func; then
520	echo failed
521	fi
522
523	echo 'should not get here'
524
525	## status: 1
526	## STDOUT:
527	## END
528	## N-I dash/bash/mksh/ash status: 0
529	## N-I dash/bash/mksh/ash STDOUT:
530	one
531	two
532	should not get here
533	## END
534
535	#### command_sub_errexit causes local d=$(date %x) to fail
536	set -o errexit
537	shopt -s inherit_errexit || true
538	#shopt -s strict_errexit || true
539	shopt -s command_sub_errexit || true
540
541	myproc() {
542	# this is disallowed because we want a runtime error 100% of the time
543	local x=$(true)
544
545	# Realistic example. Should fail here but shells don't!
546	local d=$(date %x)
547	echo hi
548	}
549	myproc
550
551	## status: 1
552	## STDOUT:
553	## END
554	## N-I dash/bash/mksh/ash status: 0
555	## N-I dash/bash/mksh/ash STDOUT:
556	hi
557	## END
558
559	#### command_sub_errexit and command sub in array
560	case $SH in (dash|ash|mksh) exit ;; esac
561
562	set -o errexit
563	shopt -s inherit_errexit || true
564	#shopt -s strict_errexit || true
565	shopt -s command_sub_errexit || true
566
567	# We don't want silent failure here
568	readonly -a myarray=( one "$(date %x)" two )
569
570	#echo len=${#myarray[@]}
571	argv.py "${myarray[@]}"
572	## status: 1
573	## STDOUT:
574	## END
575	## N-I bash status: 0
576	## N-I bash STDOUT:
577	['one', '', 'two']
578	## END
579	## N-I dash/ash/mksh status: 0
580