1	#!/usr/bin/env bash
2
3	# NOTE on bash bug: After setting IFS to array, it never splits anymore? Even
4	# if you assign IFS again.
5
6	### IFS is scoped
7	IFS=b
8	word=abcd
9	f() { local IFS=c; argv.py $word; }
10	f
11	argv.py $word
12	# stdout-json: "['ab', 'd']\n['a', 'cd']\n"
13
14	### Tilde sub is not split, but var sub is
15	HOME="foo bar"
16	argv.py ~
17	argv.py $HOME
18	# stdout-json: "['foo bar']\n['foo', 'bar']\n"
19
20	### Word splitting
21	a="1 2"
22	b="3 4"
23	argv.py $a"$b"
24	# stdout-json: "['1', '23 4']\n"
25
26	### Word splitting 2
27	a="1 2"
28	b="3 4"
29	c="5 6"
30	d="7 8"
31	argv.py $a"$b"$c"$d"
32	# stdout-json: "['1', '23 45', '67 8']\n"
33
34	# Has tests on differences between $* "$*" $@ "$@"
35	# http://stackoverflow.com/questions/448407/bash-script-to-receive-and-repass-quoted-parameters
36
37	### $*
38	func() { argv.py -$*-; }
39	func "a 1" "b 2" "c 3"
40	# stdout: ['-a', '1', 'b', '2', 'c', '3-']
41
42	### "$*"
43	func() { argv.py "-$*-"; }
44	func "a 1" "b 2" "c 3"
45	# stdout: ['-a 1 b 2 c 3-']
46
47	### $@
48	# How does this differ from $* ? I don't think it does.
49	func() { argv.py -$@-; }
50	func "a 1" "b 2" "c 3"
51	# stdout: ['-a', '1', 'b', '2', 'c', '3-']
52
53	### "$@"
54	func() { argv.py "-$@-"; }
55	func "a 1" "b 2" "c 3"
56	# stdout: ['-a 1', 'b 2', 'c 3-']
57
58	### empty argv
59	argv.py 1 "$@" 2 $@ 3 "$*" 4 $* 5
60	# stdout: ['1', '2', '3', '', '4', '5']
61
62	### Word elision with space
63	s1=' '
64	argv.py $s1
65	# stdout: []
66
67	### Word elision with non-whitespace IFS
68	# Treated differently than the default IFS. What is the rule here?
69	IFS='_'
70	char='_'
71	space=' '
72	empty=''
73	argv.py $char
74	argv.py $space
75	argv.py $empty
76	## STDOUT:
77	['']
78	[' ']
79	[]
80	## END
81
82	### Leading/trailing word elision with non-whitespace IFS
83	# This behavior is weird.
84	IFS=_
85	s1='_a_b_'
86	argv.py $s1
87	# stdout: ['', 'a', 'b']
88
89	### Leading ' ' vs leading ' _ '
90	# This behavior is weird, but all shells agree.
91	IFS='_ '
92	s1='_ a b _ '
93	s2=' a b _ '
94	argv.py $s1
95	argv.py $s2
96	## STDOUT:
97	['', 'a', 'b']
98	['a', 'b']
99	## END
100
101	### Multiple non-whitespace IFS chars.
102	IFS=_-
103	s1='a__b---c_d'
104	argv.py $s1
105	# stdout: ['a', '', 'b', '', '', 'c', 'd']
106
107	### IFS with whitespace and non-whitepace.
108	# NOTE: Three delimiters means two empty words in the middle. No elision.
109	IFS='_ '
110	s1='a_b _ _ _ c _d e'
111	argv.py $s1
112	# stdout: ['a', 'b', '', '', 'c', 'd', 'e']
113
114	### empty $@ and $* is elided
115	func() { argv.py 1 $@ $* 2; }
116	func
117	# stdout: ['1', '2']
118
119	### unquoted empty arg is elided
120	empty=""
121	argv.py 1 $empty 2
122	# stdout: ['1', '2']
123
124	### unquoted whitespace arg is elided
125	space=" "
126	argv.py 1 $space 2
127	# stdout: ['1', '2']
128
129	### empty literals are not elided
130	space=" "
131	argv.py 1 $space"" 2
132	# stdout: ['1', '', '2']
133
134	### no splitting when IFS is empty
135	IFS=""
136	foo="a b"
137	argv.py $foo
138	# stdout: ['a b']
139
140	### default value can yield multiple words
141	argv.py 1 ${undefined:-"2 3" "4 5"} 6
142	# stdout: ['1', '2 3', '4 5', '6']
143
144	### default value can yield multiple words with part joining
145	argv.py 1${undefined:-"2 3" "4 5"}6
146	# stdout: ['12 3', '4 56']
147
148	### default value with unquoted IFS char
149	IFS=_
150	argv.py 1${undefined:-"2_3"x_x"4_5"}6
151	# stdout: ['12_3x', 'x4_56']
152
153	### IFS empty doesn't do splitting
154	IFS=''
155	x=$(echo -e ' a b\tc\n')
156	argv $x
157	## STDOUT:
158	[' a b\tc']
159	## END
160	## N-I dash STDOUT:
161	['-e a b\tc']
162	## END
163
164
165	### IFS unset behaves like $' \t\n'
166	unset IFS
167	x=$(echo -e ' a b\tc\n')
168	argv $x
169	## STDOUT:
170	['a', 'b', 'c']
171	## END
172	## N-I dash STDOUT:
173	['-e', 'a', 'b', 'c']
174	## END
175
176
177	# TODO:
178	# - unquoted args of whitespace are not elided (when IFS = null)
179	# - empty quoted args are kept
180	# - Test ${@:1} and so forth?
181	#
182	# - $* $@ with empty IFS
183	# - $* $@ with custom IFS
184	#
185	# - no splitting when IFS is empty
186	# - word splitting removes leading and trailing whitespace
187
188	# TODO: test framework needs common setup
189
190	# Test IFS and $@ $* on all these
191	### TODO
192	empty=""
193	space=" "
194	AB="A B"
195	X="X"
196	Yspaces=" Y "
197