1	#!/bin/bash
2
3	### String length
4	v=foo
5	echo ${#v}
6	# stdout: 3
7
8	### Substring
9	v=abcde
10	echo ${v:1:3}
11	# stdout: bcd
12	# N-I dash status: 2
13	# N-I dash stdout-json: ""
14
15	### Cannot take length of substring
16	# These are runtime errors, but we could make them parse time errors.
17	v=abcde
18	echo ${#v:1:3}
19	# status: 1
20	# N-I dash status: 0
21	# N-I dash stdout: 5
22
23	### Pattern replacement
24	v=abcde
25	echo ${v/c*/XX}
26	# stdout: abXX
27	# N-I dash status: 2
28	# N-I dash stdout-json: ""
29
30	### Remove smallest suffix
31	v=aabbccdd
32	echo ${v%c*}
33	# stdout: aabbc
34
35	### Remove longest suffix
36	v=aabbccdd
37	echo ${v%%c*}
38	# stdout: aabb
39
40	### Remove smallest prefix
41	v=aabbccdd
42	echo ${v#*b}
43	# stdout: bccdd
44
45	### Remove longest prefix
46	v=aabbccdd
47	echo ${v##*b}
48	# stdout: ccdd
49
50	### Default value when empty
51	empty=''
52	echo ${empty:-is empty}
53	# stdout: is empty
54
55	### Default value when unset
56	echo ${unset-is unset}
57	# stdout: is unset
58
59	### Assign default value when empty
60	empty=''
61	${empty:=is empty}
62	echo $empty
63	# stdout: is empty
64
65	### Assign default value when unset
66	${unset=is unset}
67	echo $unset
68	# stdout: is unset
69
70	### Alternative value when empty
71	v=foo
72	empty=''
73	echo ${v:+v is not empty} ${empty:+is not empty}
74	# stdout: v is not empty
75
76	### Alternative value when unset
77	v=foo
78	echo ${v+v is not unset} ${unset:+is not unset}
79	# stdout: v is not unset
80
81	### Error when empty
82	empty=''
83	${empty:?is empty}
84	# status: 1
85	# OK dash status: 2
86
87	### Error when unset
88	${unset?is empty}
89	# status: 1
90	# OK dash status: 2
91
92	### Error when unset
93	v=foo
94	echo ${v+v is not unset} ${unset:+is not unset}
95	# stdout: v is not unset
96
97	### String slice
98	foo=abcdefg
99	echo ${foo:1:3}
100	# stdout: bcd
101	# N-I dash status: 2
102	# N-I dash stdout-json: ""
103
104	### Negative string slice
105	foo=abcdefg
106	echo ${foo: -4:3}
107	# stdout: def
108	# N-I dash status: 2
109	# N-I dash stdout-json: ""
110
111	### String slice with math
112	# I think this is the $(()) language inside?
113	i=1
114	foo=abcdefg
115	echo ${foo: i-3-2 : i + 2}
116	# stdout: def
117	# N-I dash status: 2
118	# N-I dash stdout-json: ""
119
120	### Var ref with ${!a}
121	a=b
122	b=c
123	echo ref ${!a}
124	# Woah mksh has a completely different behavior -- var name, not var ref.
125	# stdout: ref c
126	# BUG mksh stdout: ref a
127	# N-I dash/zsh stdout-json: ""
128
129	### Bad var ref with ${!a}
130	#set -o nounset
131	a='bad var name'
132	echo ref ${!a}
133	# Woah even dash implements this!
134	# stdout-json: "ref\n"
135	# BUG mksh stdout: ref a
136	# N-I dash/zsh stdout-json: ""
137
138	### Local Var
139	# Oh this is interesting. Local vars in a function are visible to the function
140	# it calls. That is not how functions work! Functions are supposed to take
141	# params.
142	f() {
143	local f_var=5
144	g
145	}
146	g() {
147	local g_var=6
148	echo INNER $f_var $g_var
149	}
150	f
151	echo "OUTER" $f_var $g_var
152	# stdout-json: "INNER 5 6\nOUTER\n"
153
154	### Nested ${}
155	bar=ZZ
156	echo ${foo:-${bar}}
157	# stdout: ZZ
158
159	### Braced block inside ${}
160	# NOTE: This doesn't work in bash. The nested {} aren't parsed. It works in
161	# dash though!
162	# bash - line 1: syntax error near unexpected token `)'
163	# bash - line 1: `echo ${foo:-$({ which ls; })}'
164	# tag: bash-bug
165	echo ${foo:-$({ which ls; })}
166	# stdout: /bin/ls
167	# BUG bash stdout-json: ""
168	# BUG bash status: 2
169
170	### Assigning $@ to var
171	# dash doesn't like this -- says '2' bad variable name.
172	# NOTE: bash and mksh support array variables! This is probably the
173	# difference. Need to test array semantics!
174	func() {
175	local v=$@
176	argv.py $v
177	}
178	func 1 2 3
179	# stdout: ['1', '2', '3']
180	# BUG dash status: 2
181	# BUG dash stdout-json: ""
182
183	### Assigning "$@" to var
184	# dash doesn't like this -- says '2 3' bad variable name.
185	func() {
186	local v="$@"
187	argv.py $v
188	}
189	func 1 '2 3'
190	# stdout: ['1', '2', '3']
191	# BUG dash status: 2
192	# BUG dash stdout-json: ""
193
194	### Assigning "$@" to var, then showing it quoted
195	# dash doesn't like this -- says '2 3' bad variable name.
196	func() {
197	local v="$@"
198	argv.py "$v"
199	}
200	func 1 '2 3'
201	# stdout: ['1 2 3']
202	# BUG dash status: 2
203	# BUG dash stdout-json: ""
204
205	### Filename redirect with "$@"
206	# bash - ambiguous redirect -- yeah I want this error
207	# - But I want it at PARSE time? So is there a special DollarAtPart?
208	# MultipleArgsPart?
209	# mksh - tries to create '_tmp/var-sub1 _tmp/var-sub2'
210	# dash - tries to create '_tmp/var-sub1 _tmp/var-sub2'
211	func() {
212	echo hi >gt; "$@"
213	}
214	func _tmp/var-sub1 _tmp/var-sub2
215	# status: 1
216	# OK dash status: 2
217
218	### Filename redirect with split word
219	# bash - runtime error, ambiguous redirect
220	# mksh and dash - they will NOT apply word splitting after redirect, and write
221	# to '_tmp/1 2'
222	# Stricter behavior seems fine.
223	foo='_tmp/1 2'
224	rm '_tmp/1 2'
225	echo hi >gt; $foo
226	test -f '_tmp/1 2' && cat '_tmp/1 2'
227	# status: 1
228	# OK dash/mksh status: 0
229	# OK dash/mksh stdout: hi
230
231	### Descriptor redirect to bad "$@"
232	# All of them give errors:
233	# dash - bad fd number, parse error?
234	# bash - ambiguous redirect
235	# mksh - illegal file scriptor name
236	set -- '2 3' 'c d'
237	echo hi 1>gt;& "$@"
238	# status: 2
239	# OK bash/mksh status: 1
240
241	### Here doc with bad "$@" delimiter
242	# bash - syntax error
243	# dash - syntax error: end of file unexpected
244	# mksh - runtime error: here document unclosed
245	#
246	# What I want is syntax error: bad delimiter!
247	#
248	# This means that "$@" should be part of the parse tree then? Anything that
249	# involves more than one token.
250	func() {
251	cat
252	hi
253	1 2
254	}
255	func 1 2
256	# status: 2
257	# stdout-json: ""
258	# OK mksh status: 1
259
260