1	#!/usr/bin/env bash
2
3	### Leading redirect
4	echo hello >$TMP/hello.txt # temporary fix
5	<$TMP/hello.txt cat
6	# stdout: hello
7
8	### Nonexistent file
9	cat <$TMP/nonexistent.txt
10	echo status=$?
11	# stdout: status=1
12	# OK dash stdout: status=2
13
14	### No command
15	# Hm this is valid in bash and dash. It's parsed as an assigment with a
16	# redirect, which doesn't make sense. But it's a mistake, and should be a W2
17	# warning for us.
18	FOO=bar 2>/dev/null
19
20	### Redirect in subshell
21	FOO=$(echo foo 1>&2)
22	echo $FOO
23	# stdout:
24	# stderr: foo
25
26	### Redirect in assignment
27	# dash captures stderr to a file here, which seems correct. Bash doesn't and
28	# just lets it go to actual stderr.
29	# For now we agree with dash/mksh, since it involves fewer special cases in the
30	# code.
31	FOO=$(echo foo 1>&2) 2>$TMP/no-command.txt
32	echo FILE=
33	cat $TMP/no-command.txt
34	echo "FOO=$FOO"
35	# stdout-json: "FILE=\nfoo\nFOO=\n"
36	# BUG bash stdout-json: "FILE=\nFOO=\n"
37
38	### Redirect in function body.
39	func() { echo hi; } 1>&2
40	func
41	# stdout-json: ""
42	# stderr-json: "hi\n"
43
44	### Redirect in function body is evaluated multiple times
45	i=0
46	func() { echo "file $i"; } 1> "$TMP/file$((i++))"
47	func
48	func
49	echo i=$i
50	echo __
51	cat $TMP/file0
52	echo __
53	cat $TMP/file1
54	# stdout-json: "i=2\n__\nfile 1\n__\nfile 2\n"
55	# N-I dash stdout-json: ""
56	# N-I dash status: 2
57
58	### Redirect in function body AND function call
59	func() { echo hi; } 1>&2
60	func 2>&1
61	# stdout-json: "hi\n"
62	# stderr-json: ""
63
64	### Descriptor redirect with spaces
65	# Hm this seems like a failure of lookahead! The second thing should look to a
66	# file-like thing.
67	# I think this is a posix issue.
68	# tag: posix-issue
69	echo one 1>&2
70	echo two 1 >&2
71	echo three 1>& 2
72	# stderr-json: "one\ntwo 1\nthree\n"
73
74	### Filename redirect with spaces
75	# This time 1 *is* a descriptor, not a word. If you add a space between 1 and
76	# >, it doesn't work.
77	echo two 1> $TMP/file-redir1.txt
78	cat $TMP/file-redir1.txt
79	# stdout: two
80
81	### Quoted filename redirect with spaces
82	# POSIX makes node of this
83	echo two \1 > $TMP/file-redir2.txt
84	cat $TMP/file-redir2.txt
85	# stdout: two 1
86
87	### Descriptor redirect with filename
88	# bash/mksh treat this like a filename, not a descriptor.
89	# dash aborts.
90	echo one 1>&$TMP/nonexistent-filename__
91	echo "status=$?"
92	# stdout: status=1
93	# BUG bash stdout: status=0
94	# OK dash stdout-json: ""
95	# OK dash status: 2
96
97	### redirect for loop
98	for i in $(seq 3)
99	do
100	echo $i
101	done > $TMP/redirect-for-loop.txt
102	cat $TMP/redirect-for-loop.txt
103	# stdout-json: "1\n2\n3\n"
104
105	### redirect subshell
106	( echo foo ) 1>&2
107	# stderr: foo
108	# stdout-json: ""
109
110	### Prefix redirect for loop -- not allowed
111	>$TMP/redirect2.txt for i in $(seq 3)
112	do
113	echo $i
114	done
115	cat $TMP/redirect2.txt
116	# status: 2
117	# OK mksh status: 1
118
119	### Brace group redirect
120	# Suffix works, but prefix does NOT work.
121	# That comes from '| compound_command redirect_list' in the grammar!
122	{ echo block-redirect; } > $TMP/br.txt
123	cat $TMP/br.txt | wc -c
124	# stdout: 15
125
126	### Redirect echo to stderr, and then redirect all of stdout somewhere.
127	{ echo foo 1>&2; echo 012345789; } > $TMP/block-stdout.txt
128	cat $TMP/block-stdout.txt | wc -c
129	# stderr: foo
130	# stdout: 10
131
132	### Redirect in the middle of two assignments
133	FOO=foo >$TMP/out.txt BAR=bar printenv.py FOO BAR
134	tac $TMP/out.txt
135	# stdout-json: "bar\nfoo\n"
136
137	### Redirect in the middle of a command
138	f=$TMP/out
139	echo -n 1 2 '3 ' > $f
140	echo -n 4 5 >> $f '6 '
141	echo -n 7 >> $f 8 '9 '
142	echo -n >> $f 1 2 '3 '
143	echo >> $f -n 4 5 '6 '
144	cat $f
145	# stdout-json: "1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 "
146
147	### Named file descriptor
148	exec {myfd}> $TMP/named-fd.txt
149	echo named-fd-contents >& $myfd
150	cat $TMP/named-fd.txt
151	# stdout: named-fd-contents
152	# status: 0
153	# N-I dash/mksh stdout-json: ""
154	# N-I dash/mksh status: 127
155
156	### Redirect function stdout
157	f() { echo one; echo two; }
158	f > $TMP/redirect-func.txt
159	cat $TMP/redirect-func.txt
160	# stdout-json: "one\ntwo\n"
161
162	### Nested function stdout redirect
163	# Shows that a stack is necessary.
164	inner() {
165	echo i1
166	echo i2
167	}
168	outer() {
169	echo o1
170	inner > $TMP/inner.txt
171	echo o2
172	}
173	outer > $TMP/outer.txt
174	cat $TMP/inner.txt
175	echo --
176	cat $TMP/outer.txt
177	# stdout-json: "i1\ni2\n--\no1\no2\n"
178
179	### Redirect to empty string
180	f=''
181	echo s > "$f"
182	echo "result=$?"
183	set -o errexit
184	echo s > "$f"
185	echo DONE
186	# stdout: result=1
187	# status: 1
188	# OK dash stdout: result=2
189	# OK dash status: 2
190
191	### Redirect to file descriptor that's not open
192	# BUGS:
193	# - dash doesn't allow file descriptors greater than 9. (This is a good thing,
194	# because the bash chapter in AOSA book mentions that juggling user vs. system
195	# file descriptors is a huge pain.)
196	# - But somehow running in parallel under spec-runner.sh changes whether descriptor
197	# 3 is open. e.g. 'echo hi 1>&3'. Possibly because of /usr/bin/time. The
198	# _tmp/spec/*.task.txt file gets corrupted!
199	# - Oh this is because I use time --output-file. That opens descriptor 3. And
200	# then time forks the shell script. The file descriptor table is inherited.
201	# - You actually have to set the file descriptor to something. What do
202	# configure and debootstrap too?
203	echo hi 1>&9
204	# status: 1
205	# OK dash status: 2
206
207	### Open descriptor with exec
208	# What is the point of this? ./configure scripts and debootstrap use it.
209	exec 3>&1
210	echo hi 1>&3
211	# stdout: hi
212	# status: 0
213
214	### Open multiple descriptors with exec
215	# What is the point of this? ./configure scripts and debootstrap use it.
216	exec 3>&1
217	exec 4>&1
218	echo three 1>&3
219	echo four 1>&4
220	# stdout-json: "three\nfour\n"
221	# status: 0
222
223	### >| to clobber
224	echo XX >| $TMP/c.txt
225	set -o noclobber
226	echo YY > $TMP/c.txt # not globber
227	echo status=$?
228	cat $TMP/c.txt
229	echo ZZ >| $TMP/c.txt
230	cat $TMP/c.txt
231	# stdout-json: "status=1\nXX\nZZ\n"
232	# OK dash stdout-json: "status=2\nXX\nZZ\n"
233
234	### &> redirects stdout and stderr
235	stdout_stderr.py &> $TMP/f.txt
236	# order is indeterminate
237	grep STDOUT $TMP/f.txt >/dev/null && echo 'ok'
238	grep STDERR $TMP/f.txt >/dev/null && echo 'ok'
239	# stdout-json: "ok\nok\n"
240	# N-I dash stdout: STDOUT
241	# N-I dash stderr: STDERR
242	# N-I dash status: 1
243
244	### 1>&2- to close file descriptor
245	# NOTE: "hi\n" goes to stderr, but it's hard to test this because other shells
246	# put errors on stderr.
247	echo hi 1>&2-
248	# stdout-json: ""
249	# N-I dash status: 2
250	# N-I dash stdout-json: ""
251	# N-I mksh status: 1
252	# N-I mksh stdout-json: ""
253
254	### <> for read/write
255	echo first >$TMP/rw.txt
256	exec 8<>$TMP/rw.txt
257	read line <&8
258	echo line=$line
259	echo second 1>&8
260	echo CONTENTS
261	cat $TMP/rw.txt
262	# stdout-json: "line=first\nCONTENTS\nfirst\nsecond\n"