1	#!/usr/bin/env bash
2	#
3	# Tests for pipelines.
4	# NOTE: Grammatically, ! is part of the pipeline:
5	#
6	# pipeline : pipe_sequence
7	# | Bang pipe_sequence
8
9	### Brace group in pipeline
10	{ echo one; echo two; } | tac
11	# stdout-json: "two\none\n"
12
13	### For loop starts pipeline
14	for w in one two; do
15	echo $w
16	done | tac
17	# stdout-json: "two\none\n"
18
19	### While Loop ends pipeline
20	seq 3 | while read i
21	do
22	echo ".$i"
23	done
24	# stdout-json: ".1\n.2\n.3\n"
25
26	### Redirect in Pipeline
27	echo hi 1>&2 | wc -l
28	# stdout: 0
29	# BUG zsh stdout: 1
30
31	### Pipeline comments
32	echo abcd | # input
33	# blank line
34	tr a-z A-Z # transform
35	# stdout: ABCD
36
37	### Exit code is last status
38	echo a | egrep '[0-9]+'
39	# status: 1
40
41	### PIPESTATUS
42	{ sleep 0.03; exit 1; } | { sleep 0.02; exit 2; } | { sleep 0.01; exit 3; }
43	echo ${PIPESTATUS[@]}
44	# stdout: 1 2 3
45	# N-I dash status: 2
46	# N-I zsh status: 3
47	# N-I dash/zsh stdout-json: ""
48
49	### |&
50	stdout_stderr.py |& cat
51	# stdout-json: "STDERR\nSTDOUT\n"
52	# status: 0
53	# N-I dash/mksh stdout-json: ""
54	# N-I dash status: 2
55
56	### ! turns non-zero into zero
57	! $SH -c 'exit 42'; echo $?
58	# stdout: 0
59	# status: 0
60
61	### ! turns zero into 1
62	! $SH -c 'exit 0'; echo $?
63	# stdout: 1
64	# status: 0
65
66	### ! in if
67	if ! echo hi; then
68	echo TRUE
69	else
70	echo FALSE
71	fi
72	# stdout-json: "hi\nFALSE\n"
73	# status: 0
74
75	### ! with ||
76	! echo hi || echo FAILED
77	# stdout-json: "hi\nFAILED\n"
78	# status: 0
79
80	### ! with { }
81	! { echo 1; echo 2; } || echo FAILED
82	# stdout-json: "1\n2\nFAILED\n"
83	# status: 0
84
85	### ! with ( )
86	! ( echo 1; echo 2 ) || echo FAILED
87	# stdout-json: "1\n2\nFAILED\n"
88	# status: 0
89
90	### ! is not a command
91	v='!'
92	$v echo hi
93	# status: 127
94
95	### Evaluation of argv[0] in pipeline occurs in child
96	${cmd=echo} hi | wc -l
97	echo "cmd=$cmd"
98	# stdout-json: "1\ncmd=\n"
99	# BUG zsh stdout-json: "1\ncmd=echo\n"
100
101	### last command is run in its own process
102	echo hi | read line
103	echo "line=$line"
104	# stdout: line=
105	# OK zsh stdout: line=hi
106
107	### shopt -s lastpipe
108	shopt -s lastpipe
109	echo hi | read line
110	echo "line=$line"
111	# stdout: line=hi
112	# N-I dash/mksh stdout: line=
113
114	### shopt -s lastpipe
115	shopt -s lastpipe
116	i=0
117	seq 3 | while read line; do
118	(( i++ ))
119	done
120	echo i=$i
121	# stdout: i=3
122	# N-I dash/mksh stdout: i=0
123