1	#!/usr/bin/env bash
2	#
3	# NOTE:
4	# - $! is tested in background.test.sh
5	# - $- is tested in sh-options
6	#
7	# TODO: It would be nice to make a table, like:
8	#
9	# $$ $BASHPID $PPID $SHLVL $BASH_SUBSHELL
10	# X
11	# (Subshell, Command Sub, Pipeline, Spawn $0)
12	#
13	# And see whether the variable changed.
14
15	#### $PWD is set
16	# Just test that it has a slash for now.
17	echo $PWD | grep /
18	## status: 0
19
20	#### $PWD is not only set, but exported
21	env | grep PWD
22	## status: 0
23	## BUG mksh status: 1
24
25	#### $HOME is NOT set
26	case $SH in *zsh) echo 'zsh sets HOME'; exit ;; esac
27
28	home=$(echo $HOME)
29	test "$home" = ""
30	echo status=$?
31
32	env | grep HOME
33	echo status=$?
34
35	# not in interactive shell either
36	$SH -i -c 'echo $HOME' | grep /
37	echo status=$?
38
39	## STDOUT:
40	status=0
41	status=1
42	status=1
43	## END
44	## BUG zsh STDOUT:
45	zsh sets HOME
46	## END
47
48
49	#### $1 .. $9 are scoped, while $0 is not
50	fun() { echo $0 $1 $2 | sed -e 's/.*sh/sh/'; }
51	fun a b
52	## stdout: sh a b
53	## BUG zsh stdout: fun a b
54
55	#### $?
56	echo $? # starts out as 0
57	sh -c 'exit 33'
58	echo $?
59	## STDOUT:
60	0
61	33
62	## END
63	## status: 0
64
65	#### $#
66	set -- 1 2 3 4
67	echo $#
68	## stdout: 4
69	## status: 0
70
71	#### $_
72	# This is bash-specific.
73	echo hi
74	echo $_
75	## stdout-json: "hi\nhi\n"
76	## N-I dash/mksh stdout-json: "hi\n\n"
77
78	#### $$ looks like a PID
79	# Just test that it has decimal digits
80	echo $$ | egrep '[0-9]+'
81	## status: 0
82
83	#### $$ doesn't change with subshell or command sub
84	# Just test that it has decimal digits
85	set -o errexit
86	die() {
87	echo 1>&2 "$@"; exit 1
88	}
89	parent=$$
90	test -n "$parent" || die "empty PID in parent"
91	( child=$$
92	test -n "$child" || die "empty PID in subshell"
93	test "$parent" = "$child" || die "should be equal: $parent != $child"
94	echo 'subshell OK'
95	)
96	echo $( child=$$
97	test -n "$child" || die "empty PID in command sub"
98	test "$parent" = "$child" || die "should be equal: $parent != $child"
99	echo 'command sub OK'
100	)
101	exit 3 # make sure we got here
102	## status: 3
103	## STDOUT:
104	subshell OK
105	command sub OK
106	## END
107
108	#### $BASHPID DOES change with subshell and command sub
109	set -o errexit
110	die() {
111	echo 1>&2 "$@"; exit 1
112	}
113	parent=$BASHPID
114	test -n "$parent" || die "empty BASHPID in parent"
115	( child=$BASHPID
116	test -n "$child" || die "empty BASHPID in subshell"
117	test "$parent" != "$child" || die "should not be equal: $parent = $child"
118	echo 'subshell OK'
119	)
120	echo $( child=$BASHPID
121	test -n "$child" || die "empty BASHPID in command sub"
122	test "$parent" != "$child" ||
123	die "should not be equal: $parent = $child"
124	echo 'command sub OK'
125	)
126	exit 3 # make sure we got here
127
128	# mksh also implements BASHPID!
129
130	## status: 3
131	## STDOUT:
132	subshell OK
133	command sub OK
134	## END
135	## N-I dash/zsh status: 1
136	## N-I dash/zsh stdout-json: ""
137
138	#### Background PID $! looks like a PID
139	sleep 0.01 &
140	pid=$!
141	wait
142	echo $pid | egrep '[0-9]+' >/dev/null
143	echo status=$?
144	## stdout: status=0
145
146	#### $PPID
147	echo $PPID | egrep '[0-9]+'
148	## status: 0
149
150	# NOTE: There is also $BASHPID
151
152	#### $PIPESTATUS
153	echo hi | sh -c 'cat; exit 33' | wc -l >/dev/null
154	argv.py "${PIPESTATUS[@]}"
155	## status: 0
156	## STDOUT:
157	['0', '33', '0']
158	## END
159	## N-I dash stdout-json: ""
160	## N-I dash status: 2
161	## N-I zsh STDOUT:
162	['']
163	## END
164
165	#### $RANDOM
166	expr $0 : '.*/osh$' && exit 99 # Disabled because of spec-runner.sh issue
167	echo $RANDOM | egrep '[0-9]+'
168	## status: 0
169	## N-I dash status: 1
170
171	#### $UID and $EUID
172	# These are both bash-specific.
173	set -o errexit
174	echo $UID | egrep -o '[0-9]+' >/dev/null
175	echo $EUID | egrep -o '[0-9]+' >/dev/null
176	echo status=$?
177	## stdout: status=0
178	## N-I dash/mksh stdout-json: ""
179	## N-I dash/mksh status: 1
180
181	#### $OSTYPE is non-empty
182	test -n "$OSTYPE"
183	echo status=$?
184	## STDOUT:
185	status=0
186	## END
187	## N-I dash/mksh STDOUT:
188	status=1
189	## END
190
191	#### $HOSTNAME
192	test "$HOSTNAME" = "$(hostname)"
193	echo status=$?
194	## STDOUT:
195	status=0
196	## END
197	## N-I dash/mksh/zsh STDOUT:
198	status=1
199	## END
200
201	#### $LINENO is the current line, not line of function call
202	echo $LINENO # first line
203	g() {
204	argv.py $LINENO # line 3
205	}
206	f() {
207	argv.py $LINENO # line 6
208	g
209	argv.py $LINENO # line 8
210	}
211	f
212	## STDOUT:
213	1
214	['6']
215	['3']
216	['8']
217	## END
218	## BUG zsh STDOUT:
219	1
220	['1']
221	['1']
222	['3']
223	## END
224	## BUG dash STDOUT:
225	1
226	['2']
227	['2']
228	['4']
229	## END
230
231	#### $LINENO in "bare" redirect arg (bug regression)
232	filename=$TMP/bare3
233	rm -f $filename
234	> $TMP/bare$LINENO
235	test -f $filename && echo written
236	echo $LINENO
237	## STDOUT:
238	written
239	5
240	## END
241	## BUG zsh STDOUT:
242	## END
243
244	#### $LINENO in redirect arg (bug regression)
245	filename=$TMP/lineno_regression3
246	rm -f $filename
247	echo x > $TMP/lineno_regression$LINENO
248	test -f $filename && echo written
249	echo $LINENO
250	## STDOUT:
251	written
252	5
253	## END
254
255	#### $LINENO for [[
256	echo one
257	[[ $LINENO -eq 2 ]] && echo OK
258	## STDOUT:
259	one
260	OK
261	## END
262	## N-I dash status: 127
263	## N-I dash stdout: one
264	## N-I mksh status: 1
265	## N-I mksh stdout: one
266
267	#### $LINENO for ((
268	echo one
269	(( x = LINENO ))
270	echo $x
271	## STDOUT:
272	one
273	2
274	## END
275	## N-I dash stdout-json: "one\n\n"
276
277	#### $LINENO in for loop
278	# hm bash doesn't take into account the word break. That's OK; we won't either.
279	echo one
280	for x in \
281	$LINENO zzz; do
282	echo $x
283	done
284	## STDOUT:
285	one
286	2
287	zzz
288	## END
289	## OK mksh STDOUT:
290	one
291	1
292	zzz
293	## END
294
295	#### $LINENO in other for loops
296	set -- a b c
297	for x; do
298	echo $LINENO $x
299	done
300	## STDOUT:
301	3 a
302	3 b
303	3 c
304	## END
305
306	#### $LINENO in for (( loop
307	# This is a real edge case that I'm not sure we care about. We would have to
308	# change the span ID inside the loop to make it really correct.
309	echo one
310	for (( i = 0; i < $LINENO; i++ )); do
311	echo $i
312	done
313	## STDOUT:
314	one
315	0
316	1
317	## END
318	## N-I dash stdout: one
319	## N-I dash status: 2
320	## BUG mksh stdout: one
321	## BUG mksh status: 1
322
323	#### $LINENO for assignment
324	a1=$LINENO a2=$LINENO
325	b1=$LINENO b2=$LINENO
326	echo $a1 $a2
327	echo $b1 $b2
328	## STDOUT:
329	1 1
330	2 2
331	## END
332
333
334	#### $_
335	: 1
336	echo $_
337	: 'foo'"bar"
338	echo $_
339	## STDOUT:
340	1
341	foobar
342	## END
343	## N-I dash/mksh stdout-json: "\n\n"
344
345	#### $_ with assignments, arrays, etc.
346	case $SH in (dash|mksh) exit ;; esac
347
348	: foo
349	echo $_
350
351	s=bar
352	echo s:$_
353
354	# zsh uses declare; bash uses s=bar
355	declare s=bar
356	echo s:$_
357
358	# zsh remains s:declare, bash resets it
359	a=(1 2)
360	echo a:$_
361
362	# zsh sets it to declare, bash uses the LHS a
363	declare a=(1 2)
364	echo a:$_
365
366	declare -g a=(1 2)
367	echo flag:$_
368
369	## STDOUT:
370	foo
371	s:
372	s:s=bar
373	a:
374	a:a
375	flag:a
376	## END
377	## OK zsh STDOUT:
378	foo
379	s:
380	s:declare
381	a:s:declare
382	a:declare
383	flag:-g
384	## END
385	## N-I dash/mksh stdout-json: ""
386
387	#### $_ undefined
388	set -e
389
390	# seems to be set to $0 at first, interesting.
391	x=$($SH -u -c 'echo $_')
392	test -n "$x"
393	echo nonempty=$?
394	## STDOUT:
395	nonempty=0
396	## END
397	## OK zsh status: 1
398	## OK zsh stdout-json: ""
399	## N-I dash status: 2
400	## N-I dash stdout-json: ""
401
402	#### BASH_VERSION / OIL_VERSION
403	case $SH in
404	(bash)
405	# BASH_VERSION=zz
406
407	echo $BASH_VERSION | egrep -o '4\.4\.0' > /dev/null
408	echo matched=$?
409	;;
410	(*osh)
411	# note: version string is mutable like in bash. I guess that's useful for
412	# testing? We might want a strict mode to eliminate that?
413
414	echo $OIL_VERSION | egrep -o '[0-9]\.[0-9]\.' > /dev/null
415	echo matched=$?
416	;;
417	(*)
418	echo 'no version'
419	;;
420	esac
421	## STDOUT:
422	matched=0
423	## END
424	## N-I dash/mksh/zsh STDOUT:
425	no version
426	## END