1	#
2	# POSIX rule about special builtins pointed at:
3	#
4	# https://www.reddit.com/r/oilshell/comments/5ykpi3/oildev_is_alive/
5
6	#### : is special and prefix assignments persist after special builtins
7	case $SH in
8	dash|zsh|*osh)
9	;;
10	*)
11	# for bash
12	set -o posix
13	;;
14	esac
15	foo=bar :
16	echo foo=$foo
17	## STDOUT:
18	foo=bar
19	## END
20	## BUG zsh STDOUT:
21	foo=
22	## END
23
24	#### readonly is special and prefix assignments persist
25
26	# Bash only implements it behind the posix option
27	case $SH in
28	dash|zsh|*osh)
29	;;
30	*)
31	# for bash
32	set -o posix
33	;;
34	esac
35	foo=bar readonly spam=eggs
36	echo foo=$foo
37	echo spam=$spam
38
39	# should NOT be exported
40	printenv.py foo
41	printenv.py spam
42	## STDOUT:
43	foo=bar
44	spam=eggs
45	None
46	None
47	## END
48	## BUG bash STDOUT:
49	foo=bar
50	spam=eggs
51	bar
52	None
53	## END
54
55	#### true is not special
56	foo=bar true
57	echo $foo
58	## stdout:
59
60	#### Shift is special and the whole script exits if it returns non-zero
61	test -n "$BASH_VERSION" && set -o posix
62	set -- a b
63	shift 3
64	echo status=$?
65	## stdout-json: ""
66	## status: 1
67	## OK dash status: 2
68	## BUG bash/zsh status: 0
69	## BUG bash/zsh STDOUT:
70	status=1
71	## END
72
73	#### set is special and fails, even if using || true
74	shopt -s invalid_ || true
75	echo ok
76	set -o invalid_ || true
77	echo should not get here
78	## STDOUT:
79	ok
80	## END
81	## status: 1
82	## OK dash status: 2
83	## BUG bash status: 0
84	## BUG bash STDOUT:
85	ok
86	should not get here
87	## END
88
89	#### Special builtins can't be redefined as functions
90	# bash manual says they are 'found before' functions.
91	test -n "$BASH_VERSION" && set -o posix
92	export() {
93	echo 'export func'
94	}
95	export hi
96	echo status=$?
97	## status: 2
98	## BUG mksh/zsh status: 0
99	## BUG mksh/zsh stdout: status=0
100
101	#### Non-special builtins CAN be redefined as functions
102	test -n "$BASH_VERSION" && set -o posix
103	true() {
104	echo 'true func'
105	}
106	true hi
107	echo status=$?
108	## STDOUT:
109	true func
110	status=0
111	## END