1	#
2	# NOTE:
3	# - $! is tested in background.test.sh
4	# - $- is tested in sh-options
5	#
6	# TODO: It would be nice to make a table, like:
7	#
8	# $$ $BASHPID $PPID $SHLVL $BASH_SUBSHELL
9	# X
10	# (Subshell, Command Sub, Pipeline, Spawn $0)
11	#
12	# And see whether the variable changed.
13
14	#### $PWD is set
15	# Just test that it has a slash for now.
16	echo $PWD | grep /
17	## status: 0
18
19	#### $PWD is not only set, but exported
20	env | grep PWD
21	## status: 0
22	## BUG mksh status: 1
23
24	#### $PATH is set if unset at startup
25
26	# Get absolute path before changing PATH
27	sh=$(which $SH)
28
29	old_path=$PATH
30	unset PATH
31
32	$sh -c 'echo $PATH' > path.txt
33
34	PATH=$old_path
35
36	# looks like PATH=/usr/bin:/bin for mksh, but more complicated for others
37	# cat path.txt
38
39	# should contain /usr/bin
40	if egrep -q '(^|:)/usr/bin($|:)' path.txt; then
41	echo yes
42	fi
43
44	# should contain /bin
45	if egrep -q '(^|:)/bin($|:)' path.txt ; then
46	echo yes
47	fi
48
49	## STDOUT:
50	yes
51	yes
52	## END
53
54
55	#### $HOME is NOT set
56	case $SH in *zsh) echo 'zsh sets HOME'; exit ;; esac
57
58	home=$(echo $HOME)
59	test "$home" = ""
60	echo status=$?
61
62	env | grep HOME
63	echo status=$?
64
65	# not in interactive shell either
66	$SH -i -c 'echo $HOME' | grep /
67	echo status=$?
68
69	## STDOUT:
70	status=0
71	status=1
72	status=1
73	## END
74	## BUG zsh STDOUT:
75	zsh sets HOME
76	## END
77
78
79	#### $1 .. $9 are scoped, while $0 is not
80	fun() { echo $0 $1 $2 | sed -e 's/.*sh/sh/'; }
81	fun a b
82	## stdout: sh a b
83	## BUG zsh stdout: fun a b
84
85	#### $?
86	echo $? # starts out as 0
87	sh -c 'exit 33'
88	echo $?
89	## STDOUT:
90	0
91	33
92	## END
93	## status: 0
94
95	#### $#
96	set -- 1 2 3 4
97	echo $#
98	## stdout: 4
99	## status: 0
100
101	#### $$ looks like a PID
102	# Just test that it has decimal digits
103	echo $$ | egrep '[0-9]+'
104	## status: 0
105
106	#### $$ doesn't change with subshell or command sub
107	# Just test that it has decimal digits
108	set -o errexit
109	die() {
110	echo 1>&2 "$@"; exit 1
111	}
112	parent=$$
113	test -n "$parent" || die "empty PID in parent"
114	( child=$$
115	test -n "$child" || die "empty PID in subshell"
116	test "$parent" = "$child" || die "should be equal: $parent != $child"
117	echo 'subshell OK'
118	)
119	echo $( child=$$
120	test -n "$child" || die "empty PID in command sub"
121	test "$parent" = "$child" || die "should be equal: $parent != $child"
122	echo 'command sub OK'
123	)
124	exit 3 # make sure we got here
125	## status: 3
126	## STDOUT:
127	subshell OK
128	command sub OK
129	## END
130
131	#### $BASHPID DOES change with subshell and command sub
132	set -o errexit
133	die() {
134	echo 1>&2 "$@"; exit 1
135	}
136	parent=$BASHPID
137	test -n "$parent" || die "empty BASHPID in parent"
138	( child=$BASHPID
139	test -n "$child" || die "empty BASHPID in subshell"
140	test "$parent" != "$child" || die "should not be equal: $parent = $child"
141	echo 'subshell OK'
142	)
143	echo $( child=$BASHPID
144	test -n "$child" || die "empty BASHPID in command sub"
145	test "$parent" != "$child" ||
146	die "should not be equal: $parent = $child"
147	echo 'command sub OK'
148	)
149	exit 3 # make sure we got here
150
151	# mksh also implements BASHPID!
152
153	## status: 3
154	## STDOUT:
155	subshell OK
156	command sub OK
157	## END
158	## N-I dash/zsh status: 1
159	## N-I dash/zsh stdout-json: ""
160
161	#### Background PID $! looks like a PID
162	sleep 0.01 &
163	pid=$!
164	wait
165	echo $pid | egrep '[0-9]+' >/dev/null
166	echo status=$?
167	## stdout: status=0
168
169	#### $PPID
170	echo $PPID | egrep '[0-9]+'
171	## status: 0
172
173	# NOTE: There is also $BASHPID
174
175	#### $PIPESTATUS
176	echo hi | sh -c 'cat; exit 33' | wc -l >/dev/null
177	argv.py "${PIPESTATUS[@]}"
178	## status: 0
179	## STDOUT:
180	['0', '33', '0']
181	## END
182	## N-I dash stdout-json: ""
183	## N-I dash status: 2
184	## N-I zsh STDOUT:
185	['']
186	## END
187
188	#### $RANDOM
189	expr $0 : '.*/osh$' && exit 99 # Disabled because of spec-runner.sh issue
190	echo $RANDOM | egrep '[0-9]+'
191	## status: 0
192	## N-I dash status: 1
193
194	#### $UID and $EUID
195	# These are both bash-specific.
196	set -o errexit
197	echo $UID | egrep -o '[0-9]+' >/dev/null
198	echo $EUID | egrep -o '[0-9]+' >/dev/null
199	echo status=$?
200	## stdout: status=0
201	## N-I dash/mksh stdout-json: ""
202	## N-I dash/mksh status: 1
203
204	#### $OSTYPE is non-empty
205	test -n "$OSTYPE"
206	echo status=$?
207	## STDOUT:
208	status=0
209	## END
210	## N-I dash/mksh STDOUT:
211	status=1
212	## END
213
214	#### $HOSTNAME
215	test "$HOSTNAME" = "$(hostname)"
216	echo status=$?
217	## STDOUT:
218	status=0
219	## END
220	## N-I dash/mksh/zsh STDOUT:
221	status=1
222	## END
223
224	#### $LINENO is the current line, not line of function call
225	echo $LINENO # first line
226	g() {
227	argv.py $LINENO # line 3
228	}
229	f() {
230	argv.py $LINENO # line 6
231	g
232	argv.py $LINENO # line 8
233	}
234	f
235	## STDOUT:
236	1
237	['6']
238	['3']
239	['8']
240	## END
241	## BUG zsh STDOUT:
242	1
243	['1']
244	['1']
245	['3']
246	## END
247	## BUG dash STDOUT:
248	1
249	['2']
250	['2']
251	['4']
252	## END
253
254	#### $LINENO in "bare" redirect arg (bug regression)
255	filename=$TMP/bare3
256	rm -f $filename
257	> $TMP/bare$LINENO
258	test -f $filename && echo written
259	echo $LINENO
260	## STDOUT:
261	written
262	5
263	## END
264	## BUG zsh STDOUT:
265	## END
266
267	#### $LINENO in redirect arg (bug regression)
268	filename=$TMP/lineno_regression3
269	rm -f $filename
270	echo x > $TMP/lineno_regression$LINENO
271	test -f $filename && echo written
272	echo $LINENO
273	## STDOUT:
274	written
275	5
276	## END
277
278	#### $LINENO in [[
279	echo one
280	[[ $LINENO -eq 2 ]] && echo OK
281	## STDOUT:
282	one
283	OK
284	## END
285	## N-I dash status: 127
286	## N-I dash stdout: one
287	## N-I mksh status: 1
288	## N-I mksh stdout: one
289
290	#### $LINENO in ((
291	echo one
292	(( x = LINENO ))
293	echo $x
294	## STDOUT:
295	one
296	2
297	## END
298	## N-I dash stdout-json: "one\n\n"
299
300	#### $LINENO in for loop
301	# hm bash doesn't take into account the word break. That's OK; we won't either.
302	echo one
303	for x in \
304	$LINENO zzz; do
305	echo $x
306	done
307	## STDOUT:
308	one
309	2
310	zzz
311	## END
312	## OK mksh STDOUT:
313	one
314	1
315	zzz
316	## END
317
318	#### $LINENO in other for loops
319	set -- a b c
320	for x; do
321	echo $LINENO $x
322	done
323	## STDOUT:
324	3 a
325	3 b
326	3 c
327	## END
328
329	#### $LINENO in for (( loop
330	# This is a real edge case that I'm not sure we care about. We would have to
331	# change the span ID inside the loop to make it really correct.
332	echo one
333	for (( i = 0; i < $LINENO; i++ )); do
334	echo $i
335	done
336	## STDOUT:
337	one
338	0
339	1
340	## END
341	## N-I dash stdout: one
342	## N-I dash status: 2
343	## BUG mksh stdout: one
344	## BUG mksh status: 1
345
346	#### $LINENO for assignment
347	a1=$LINENO a2=$LINENO
348	b1=$LINENO b2=$LINENO
349	echo $a1 $a2
350	echo $b1 $b2
351	## STDOUT:
352	1 1
353	2 2
354	## END
355
356
357	#### $_ with simple command and evaluation
358
359	name=world
360	echo "hi $name"
361	echo "$_"
362	## STDOUT:
363	hi world
364	hi world
365	## END
366	## N-I dash/mksh STDOUT:
367	hi world
368
369	## END
370
371	#### $_ and ${_}
372	case $SH in (dash|mksh) exit ;; esac
373
374	_var=value
375
376	: 42
377	echo $_ $_var ${_}var
378
379	: 'foo'"bar"
380	echo $_
381
382	## STDOUT:
383	42 value 42var
384	foobar
385	## END
386	## N-I dash/mksh stdout-json: ""
387
388	#### $_ with word splitting
389	case $SH in (dash|mksh) exit ;; esac
390
391	setopt shwordsplit # for ZSH
392
393	x='with spaces'
394	: $x
395	echo $_
396
397	## STDOUT:
398	spaces
399	## END
400	## N-I dash/mksh stdout-json: ""
401
402	#### $_ with pipeline and subshell
403	case $SH in (dash|mksh) exit ;; esac
404
405	shopt -s lastpipe
406
407	seq 3 | echo last=$_
408
409	echo pipeline=$_
410
411	( echo subshell=$_ )
412	echo done=$_
413
414	## STDOUT:
415	last=
416	pipeline=last=
417	subshell=pipeline=last=
418	done=pipeline=last=
419	## END
420
421	# very weird semantics for zsh!
422	## OK zsh STDOUT:
423	last=3
424	pipeline=last=3
425	subshell=
426	done=
427	## END
428
429	## N-I dash/mksh stdout-json: ""
430
431
432	#### $_ with && and ||
433	case $SH in (dash|mksh) exit ;; esac
434
435	echo hi && echo last=$_
436	echo and=$_
437
438	echo hi || echo last=$_
439	echo or=$_
440
441	## STDOUT:
442	hi
443	last=hi
444	and=last=hi
445	hi
446	or=hi
447	## END
448
449	## N-I dash/mksh stdout-json: ""
450
451	#### $_ is not reset with (( and [[
452
453	# bash is inconsistent because it does it for pipelines and assignments, but
454	# not (( and [[
455
456	case $SH in (dash|mksh) exit ;; esac
457
458	echo simple
459	(( a = 2 + 3 ))
460	echo "(( $_"
461
462	[[ a == *.py ]]
463	echo "[[ $_"
464
465	## STDOUT:
466	simple
467	(( simple
468	[[ (( simple
469	## END
470
471	## N-I dash/mksh stdout-json: ""
472
473
474	#### $_ with assignments, arrays, etc.
475	case $SH in (dash|mksh) exit ;; esac
476
477	: foo
478	echo "colon [$_]"
479
480	s=bar
481	echo "bare assign [$_]"
482
483	# zsh uses declare; bash uses s=bar
484	declare s=bar
485	echo "declare [$_]"
486
487	# zsh remains s:declare, bash resets it
488	a=(1 2)
489	echo "array [$_]"
490
491	# zsh sets it to declare, bash uses the LHS a
492	declare a=(1 2)
493	echo "declare array [$_]"
494
495	declare -g d=(1 2)
496	echo "declare flag [$_]"
497
498	## STDOUT:
499	colon [foo]
500	bare assign []
501	declare [s=bar]
502	array []
503	declare array [a]
504	declare flag [d]
505	## END
506
507	## OK zsh STDOUT:
508	colon [foo]
509	bare assign []
510	declare [declare]
511	array [declare [declare]]
512	declare array [declare]
513	declare flag [-g]
514	## END
515
516	## OK osh STDOUT:
517	colon [foo]
518	bare assign [colon [foo]]
519	declare [bare assign [colon [foo]]]
520	array [declare [bare assign [colon [foo]]]]
521	declare array [array [declare [bare assign [colon [foo]]]]]
522	declare flag [declare array [array [declare [bare assign [colon [foo]]]]]]
523	## END
524
525	## N-I dash/mksh stdout-json: ""
526
527	#### $_ with loop
528
529	case $SH in (dash|mksh) exit ;; esac
530
531	# zsh resets it when in a loop
532
533	echo init
534	echo begin=$_
535	for x in 1 2 3; do
536	echo prev=$_
537	done
538
539	## STDOUT:
540	init
541	begin=init
542	prev=begin=init
543	prev=prev=begin=init
544	prev=prev=prev=begin=init
545	## END
546
547	## OK zsh STDOUT:
548	init
549	begin=init
550	prev=
551	prev=prev=
552	prev=prev=prev=
553	## END
554	## N-I dash/mksh stdout-json: ""
555
556
557	#### $_ is not undefined on first use
558	set -e
559
560	x=$($SH -u -c 'echo prev=$_')
561	echo status=$?
562
563	# bash and mksh set $_ to $0 at first; zsh is empty
564	#echo "$x"
565
566	## STDOUT:
567	status=0
568	## END
569
570	## N-I dash status: 2
571	## N-I dash stdout-json: ""
572
573	#### BASH_VERSION / OIL_VERSION
574	case $SH in
575	(bash)
576	# BASH_VERSION=zz
577
578	echo $BASH_VERSION | egrep -o '4\.4\.0' > /dev/null
579	echo matched=$?
580	;;
581	(*osh)
582	# note: version string is mutable like in bash. I guess that's useful for
583	# testing? We might want a strict mode to eliminate that?
584
585	echo $OIL_VERSION | egrep -o '[0-9]+\.[0-9]+\.' > /dev/null
586	echo matched=$?
587	;;
588	(*)
589	echo 'no version'
590	;;
591	esac
592	## STDOUT:
593	matched=0
594	## END
595	## N-I dash/mksh/zsh STDOUT:
596	no version
597	## END