0
0
mirror of https://github.com/nodejs/node.git synced 2024-11-25 08:19:38 +01:00
nodejs/test/parallel/test-child-process-double-pipe.js
isaacs 3e1b1dd4a9 Remove excessive copyright/license boilerplate
The copyright and license notice is already in the LICENSE file.  There
is no justifiable reason to also require that it be included in every
file, since the individual files are not individually distributed except
as part of the entire package.
2015-01-12 15:30:28 -08:00

100 lines
2.2 KiB
JavaScript

var is_windows = process.platform === 'win32';
var common = require('../common');
var assert = require('assert'),
os = require('os'),
util = require('util'),
spawn = require('child_process').spawn;
// We're trying to reproduce:
// $ echo "hello\nnode\nand\nworld" | grep o | sed s/o/a/
var grep, sed, echo;
if (is_windows) {
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();
});
var result = '';
// print sed's output
sed.stdout.on('data', function(data) {
result += data.toString('utf8', 0, data.length);
util.print(data);
});
sed.stdout.on('end', function(code) {
assert.equal(result, 'hellO' + os.EOL + 'nOde' + os.EOL +'wOrld' + os.EOL);
});