1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
'use strict';
const common = require('../common');
const assert = require('assert');
const os = require('os');
const spawn = require('child_process').spawn;
// We're trying to reproduce:
// $ echo "hello\nnode\nand\nworld" | grep o | sed s/o/a/
let grep, sed, echo;
if (common.isWindows) {
grep = spawn('grep', ['--binary', 'o']);
sed = spawn('sed', ['--binary', 's/o/O/']);
echo = spawn('cmd.exe',
['/c', 'echo', 'hello&&', 'echo',
'node&&', 'echo', 'and&&', 'echo', 'world']);
} else {
grep = spawn('grep', ['o']);
sed = spawn('sed', ['s/o/O/']);
echo = spawn('echo', ['hello\nnode\nand\nworld\n']);
}
/*
* grep and sed hang if the spawn function leaks file descriptors to child
* processes.
* This happens when calling pipe(2) and then forgetting to set the
* FD_CLOEXEC flag on the resulting file descriptors.
*
* This test checks child processes exit, meaning they don't hang like
* explained above.
*/
// pipe echo | grep
echo.stdout.on('data', function(data) {
console.error(`grep stdin write ${data.length}`);
if (!grep.stdin.write(data)) {
echo.stdout.pause();
}
});
grep.stdin.on('drain', function(data) {
echo.stdout.resume();
});
// Propagate end from echo to grep
echo.stdout.on('end', function(code) {
grep.stdin.end();
});
echo.on('exit', function() {
console.error('echo exit');
});
grep.on('exit', function() {
console.error('grep exit');
});
sed.on('exit', function() {
console.error('sed exit');
});
// pipe grep | sed
grep.stdout.on('data', function(data) {
console.error(`grep stdout ${data.length}`);
if (!sed.stdin.write(data)) {
grep.stdout.pause();
}
});
sed.stdin.on('drain', function(data) {
grep.stdout.resume();
});
// Propagate end from grep to sed
grep.stdout.on('end', function(code) {
console.error('grep stdout end');
sed.stdin.end();
});
let result = '';
// print sed's output
sed.stdout.on('data', function(data) {
result += data.toString('utf8', 0, data.length);
console.log(data);
});
sed.stdout.on('end', function(code) {
assert.strictEqual(result, `hellO${os.EOL}nOde${os.EOL}wOrld${os.EOL}`);
});
|
