spec/builtin-special.test.sh

OILS / spec / builtin-special.test.sh View on Github | oils.pub

347 lines, 162 significant

1	## oils_failures_allowed: 0
2	## compare_shells: bash dash mksh zsh ash yash
3
4	#### true is not special; prefix assignments don't persist, it can be redefined
5	foo=bar true
6	echo foo=$foo
7
8	true() {
9	echo true func
10	}
11	foo=bar true
12	echo foo=$foo
13
14	## STDOUT:
15	foo=
16	true func
17	foo=
18	## END
19
20	## BUG mksh STDOUT:
21	foo=
22	true func
23	foo=bar
24	## END
25
26	# POSIX rule about special builtins pointed at:
27	#
28	# https://www.reddit.com/r/oilshell/comments/5ykpi3/oildev_is_alive/
29
30	#### Prefix assignments persist after special builtins, like : (set -o posix)
31	case $SH in
32	bash) set -o posix ;;
33	esac
34
35	foo=bar :
36	echo foo=$foo
37
38	# Not true when you use 'builtin'
39	z=Z builtin :
40	echo z=$Z
41
42	## STDOUT:
43	foo=bar
44	z=
45	## END
46
47	## BUG zsh STDOUT:
48	foo=
49	z=
50	## END
51
52	#### Prefix assignments persist after readonly, but NOT exported (set -o posix)
53
54	# Bash only implements it behind the posix option
55	case $SH in
56	bash) set -o posix ;;
57	esac
58	foo=bar readonly spam=eggs
59	echo foo=$foo
60	echo spam=$spam
61
62	# should NOT be exported
63	printenv.py foo
64	printenv.py spam
65
66	## STDOUT:
67	foo=bar
68	spam=eggs
69	None
70	None
71	## END
72
73	## BUG bash/yash STDOUT:
74	foo=bar
75	spam=eggs
76	bar
77	None
78	## END
79
80	#### Prefix binding to exec - adapted from toysh
81	cat > snork << 'EOF'
82	#!/bin/sh
83	echo hello $BLAH
84	EOF
85	chmod +x snork
86
87	$SH -c 'BLAH=123; ./snork'
88	$SH -c 'BLAH=123 ./snork'
89	echo
90
91	$SH -c 'BLAH=123; exec ./snork'
92	$SH -c 'BLAH=123 exec ./snork'
93	echo
94
95	# WHY different?
96	$SH -c 'BLAH=123; readonly foo; exec ./snork'
97	$SH -c 'BLAH=123 readonly foo; ./snork'
98	echo
99
100	$SH -c 'BLAH=123; : foo; exec ./snork'
101	$SH -c 'BLAH=123 : foo; ./snork'
102
103	## STDOUT:
104	hello
105	hello 123
106
107	hello
108	hello 123
109
110	hello
111	hello
112
113	hello
114	hello
115	## END
116
117	## BUG yash STDOUT:
118	hello
119	hello 123
120
121	hello
122	hello 123
123
124	hello
125	hello 123
126
127	hello
128	hello 123
129	## END
130
131	#### Prefix binding for readonly vs. exec
132
133	pre1=pre1 readonly x=x
134	pre2=pre2 exec sh -c 'echo pre1=$pre1 x=$x pre2=$pre2'
135
136	## STDOUT:
137	pre1= x= pre2=pre2
138	## END
139	## BUG yash STDOUT:
140	pre1=pre1 x= pre2=pre2
141	## END
142
143	#### Which shells allow special builtins to be redefined?
144	eval() {
145	echo 'eval func' "$@"
146	}
147	eval 'echo hi'
148
149	# we allow redefinition, but the definition is NOT used!
150	## status: 0
151	## STDOUT:
152	hi
153	## END
154
155	# we PREVENT redefinition
156	## OK dash/ash status: 2
157	## OK dash/ash STDOUT:
158	## END
159
160	# should not allow redefinition
161	## BUG bash/zsh status: 0
162	## BUG bash/zsh STDOUT:
163	eval func echo hi
164	## END
165
166
167	#### Special builtins can't be redefined as shell functions (set -o posix)
168	case $SH in
169	bash) set -o posix ;;
170	esac
171
172	eval 'echo hi'
173
174	eval() {
175	echo 'sh func' "$@"
176	}
177
178	eval 'echo hi'
179
180	## status: 0
181	## STDOUT:
182	hi
183	hi
184	## END
185
186	## OK bash/dash/ash status: 2
187	## OK bash/dash/ash STDOUT:
188	hi
189	## END
190
191	## BUG zsh status: 0
192	## BUG zsh STDOUT:
193	hi
194	sh func echo hi
195	## END
196
197	#### Non-special builtins CAN be redefined as functions
198	test -n "$BASH_VERSION" && set -o posix
199	true() {
200	echo 'true func'
201	}
202	true hi
203	echo status=$?
204	## STDOUT:
205	true func
206	status=0
207	## END
208
209	#### Shift is special and fails whole script
210
211	# https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_14
212	#
213	# 2.8.1 - Consequences of shell errors
214	#
215	# Special built-ins should exit a non-interactive shell
216	# bash and busybox dont't implement this even with set -o posix, so it seems risky
217	# dash and mksh do it; so does AT&T ksh
218
219	$SH -c '
220	if test -n "$BASH_VERSION"; then
221	set -o posix
222	fi
223	set -- a b
224	shift 3
225	echo status=$?
226	'
227	if test "$?" != 0; then
228	echo 'non-zero status'
229	fi
230
231	## STDOUT:
232	non-zero status
233	## END
234
235	## N-I bash/zsh/ash/yash/osh status: 0
236	## N-I bash/zsh/ash/yash/osh STDOUT:
237	status=1
238	## END
239
240	#### set is special and fails whole script, even if using \|\| true
241	$SH -c '
242	if test -n "$BASH_VERSION"; then
243	set -o posix
244	fi
245
246	shopt -s invalid_ \|\| true
247	echo ok
248	set -o invalid_ \|\| true
249	echo should not get here
250	'
251	if test "$?" != 0; then
252	echo 'non-zero status'
253	fi
254
255	## STDOUT:
256	ok
257	non-zero status
258	## END
259
260	## N-I bash/ash/yash/osh status: 0
261	## N-I bash/ash/yash/osh STDOUT:
262	ok
263	should not get here
264	## END
265
266	#### bash 'type' gets confused - says 'function', but runs builtin
267	case $SH in dash\|mksh\|zsh\|ash\|yash) exit ;; esac
268
269	echo TRUE
270	type -t true # builtin
271	true() { echo true func; }
272	type -t true # now a function
273	echo ---
274
275	echo EVAL
276
277	type -t eval # builtin
278	# define function before set -o posix
279	eval() { echo "shell function: $1"; }
280	# bash runs the FUNCTION, but OSH finds the special builtin
281	# OSH doesn't need set -o posix
282	eval 'echo before posix'
283
284	if test -n "$BASH_VERSION"; then
285	# this makes the eval definition invisible!
286	set -o posix
287	fi
288
289	eval 'echo after posix' # this is the builtin eval
290	# bash claims it's a function, but it's a builtin
291	type -t eval
292
293	# it finds the function and the special builtin
294	#type -a eval
295
296	## BUG bash STDOUT:
297	TRUE
298	builtin
299	function
300	---
301	EVAL
302	builtin
303	shell function: echo before posix
304	after posix
305	function
306	## END
307
308	## STDOUT:
309	TRUE
310	builtin
311	function
312	---
313	EVAL
314	builtin
315	before posix
316	after posix
317	builtin
318	## END
319
320	## N-I dash/mksh/zsh/ash/yash STDOUT:
321	## END
322
323	#### command, builtin - both can be redefined, not special (regression)
324	case $SH in dash\|ash\|yash) exit ;; esac
325
326	builtin echo b
327	command echo c
328
329	builtin() {
330	echo builtin-redef "$@"
331	}
332
333	command() {
334	echo command-redef "$@"
335	}
336
337	builtin echo b
338	command echo c
339
340	## STDOUT:
341	b
342	c
343	builtin-redef echo b
344	command-redef echo c
345	## END
346	## N-I dash/ash/yash STDOUT:
347	## END