1	#!/bin/bash
2
3	### Leading redirect
4	echo hello >$TMP/hello.txt # temporary fix
5	<$TMP/hello.txt cat
6	# stdout: hello
7
8	### No command
9	# Hm this is valid in bash and dash. It's parsed as an assigment with a
10	# redirect, which doesn't make sense. But it's a mistake, and should be a W2
11	# warning for us.
12	FOO=bar 2>/dev/null
13
14	### Redirect in subshell
15	FOO=$(echo foo 1>&2)
16	echo $FOO
17	# stdout:
18	# stderr: foo
19
20	### Redirect in assignment
21	# dash captures stderr to a file here, which seems correct. Bash doesn't and
22	# just lets it go to actual stderr.
23	# For now we agree with dash/mksh, since it involves fewer special cases in the
24	# code.
25	FOO=$(echo foo 1>&2) 2>$TMP/no-command.txt
26	echo FILE=
27	cat $TMP/no-command.txt
28	echo "FOO=$FOO"
29	# stdout-json: "FILE=\nfoo\nFOO=\n"
30	# BUG bash stdout-json: "FILE=\nFOO=\n"
31
32	### Redirect in function body.
33	func() { echo hi; } 1>&2
34	func
35	# stdout-json: ""
36	# stderr-json: "hi\n"
37
38	### Redirect in function body is evaluated multiple times
39	i=0
40	func() { echo "file $i"; } 1> "$TMP/file$((i++))"
41	func
42	func
43	echo i=$i
44	echo __
45	cat $TMP/file0
46	echo __
47	cat $TMP/file1
48	# stdout-json: "i=2\n__\nfile 1\n__\nfile 2\n"
49	# N-I dash stdout-json: ""
50	# N-I dash status: 2
51
52	### Redirect in function body AND function call
53	func() { echo hi; } 1>&2
54	func 2>&1
55	# stdout-json: "hi\n"
56	# stderr-json: ""
57
58	### Descriptor redirect with spaces
59	# Hm this seems like a failure of lookahead! The second thing should look to a
60	# file-like thing.
61	# I think this is a posix issue.
62	# tag: posix-issue
63	echo one 1>&2
64	echo two 1 >&2
65	echo three 1>& 2
66	# stderr-json: "one\ntwo 1\nthree\n"
67
68	### Filename redirect with spaces
69	# This time 1 *is* a descriptor, not a word. If you add a space between 1 and
70	# >, it doesn't work.
71	echo two 1> $TMP/file-redir1.txt
72	cat $TMP/file-redir1.txt
73	# stdout: two
74
75	### Quoted filename redirect with spaces
76	# POSIX makes node of this
77	echo two \1 > $TMP/file-redir2.txt
78	cat $TMP/file-redir2.txt
79	# stdout: two 1
80
81	### Descriptor redirect with filename
82	# bash/mksh treat this like a filename, not a descriptor.
83	# dash aborts.
84	echo one 1>&$TMP/nonexistent-filename__
85	echo "status=$?"
86	# stdout: status=1
87	# BUG bash stdout: status=0
88	# OK dash stdout-json: ""
89	# OK dash status: 2
90
91	### redirect for loop
92	for i in $(seq 3)
93	do
94	echo $i
95	done > $TMP/redirect-for-loop.txt
96	cat $TMP/redirect-for-loop.txt
97	# stdout-json: "1\n2\n3\n"
98
99	### redirect subshell
100	( echo foo ) 1>&2
101	# stderr: foo
102	# stdout-json: ""
103
104	### Prefix redirect for loop -- not allowed
105	>$TMP/redirect2.txt for i in $(seq 3)
106	do
107	echo $i
108	done
109	cat $TMP/redirect2.txt
110	# status: 2
111	# OK mksh status: 1
112
113	### Brace group redirect
114	# Suffix works, but prefix does NOT work.
115	# That comes from '| compound_command redirect_list' in the grammar!
116	{ echo block-redirect; } > $TMP/br.txt
117	cat $TMP/br.txt | wc -c
118	# stdout: 15
119
120	### Redirect echo to stderr, and then redirect all of stdout somewhere.
121	{ echo foo 1>&2; echo 012345789; } > $TMP/block-stdout.txt
122	cat $TMP/block-stdout.txt | wc -c
123	# stderr: foo
124	# stdout: 10
125
126	### Redirect in the middle of two assignments
127	FOO=foo >$TMP/out.txt BAR=bar printenv.py FOO BAR
128	tac $TMP/out.txt
129	# stdout-json: "bar\nfoo\n"
130
131	### Redirect in the middle of a command
132	f=$TMP/out
133	echo -n 1 2 '3 ' > $f
134	echo -n 4 5 >> $f '6 '
135	echo -n 7 >> $f 8 '9 '
136	echo -n >> $f 1 2 '3 '
137	echo >> $f -n 4 5 '6 '
138	cat $f
139	# stdout-json: "1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 "
140
141	### Named file descriptor
142	exec {myfd}> $TMP/named-fd.txt
143	echo named-fd-contents >& $myfd
144	cat $TMP/named-fd.txt
145	# stdout: named-fd-contents
146	# status: 0
147	# N-I dash/mksh stdout-json: ""
148	# N-I dash/mksh status: 127
149
150	### Redirect function stdout
151	f() { echo one; echo two; }
152	f > $TMP/redirect-func.txt
153	cat $TMP/redirect-func.txt
154	# stdout-json: "one\ntwo\n"
155
156	### Nested function stdout redirect
157	# Shows that a stack is necessary.
158	inner() {
159	echo i1
160	echo i2
161	}
162	outer() {
163	echo o1
164	inner > $TMP/inner.txt
165	echo o2
166	}
167	outer > $TMP/outer.txt
168	cat $TMP/inner.txt
169	echo --
170	cat $TMP/outer.txt
171	# stdout-json: "i1\ni2\n--\no1\no2\n"
172
173	### Redirect to empty string
174	f=''
175	echo s > "$f"
176	echo "result=$?"
177	set -o errexit
178	echo s > "$f"
179	echo DONE
180	# stdout: result=1
181	# status: 1
182	# OK dash stdout: result=2
183	# OK dash status: 2
184
185	### Redirect to file descriptor that's not open
186	# BUGS:
187	# - dash doesn't allow file descriptors greater than 9. (This is a good thing,
188	# because the bash chapter in AOSA book mentions that juggling user vs. system
189	# file descriptors is a huge pain.)
190	# - But somehow running in parallel under spec-runner.sh changes whether descriptor
191	# 3 is open. e.g. 'echo hi 1>&3'. Possibly because of /usr/bin/time. The
192	# _tmp/spec/*.task.txt file gets corrupted!
193	# - Oh this is because I use time --output-file. That opens descriptor 3. And
194	# then time forks the shell script. The file descriptor table is inherited.
195	# - You actually have to set the file descriptor to something. What do
196	# configure and debootstrap too?
197	echo hi 1>&9
198	# status: 1
199	# OK dash status: 2
200
201	### Open descriptor with exec
202	# What is the point of this? ./configure scripts and debootstrap use it.
203	exec 3>&1
204	echo hi 1>&3
205	# stdout: hi
206	# status: 0
207
208	### Open multiple descriptors with exxec
209	# What is the point of this? ./configure scripts and debootstrap use it.
210	exec 3>&1
211	exec 4>&1
212	echo three 1>&3
213	echo four 1>&4
214	# stdout-json: "three\nfour\n"
215	# status: 0