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child_process: new stdio API for .spawn() method

v0.9.1-release
Fedor Indutny 13 years ago
parent
commit
0262b6d2a5
  1. 50
      doc/api/child_process.markdown

50
doc/api/child_process.markdown

@ -245,6 +245,7 @@ there is no IPC channel keeping it alive. When calling this method the
* `args` {Array} List of string arguments
* `options` {Object}
* `cwd` {String} Current working directory of the child process
* `stdio` {Array|String} Child's stdio configuration. (See below)
* `customFds` {Array} **Deprecated** File descriptors for the child to use
for stdio. (See below)
* `env` {Object} Environment key-value pairs
@ -336,6 +337,47 @@ spawning the process with an empty environment rather than using
`process.env`. This due to backwards compatibility issues with a deprecated
API.
The 'stdio' option to `child_process.spawn()` is an array where each
index corresponds to a fd in the child. The value is one of the following:
1. `null`, `undefined` - Use default value. For 0,1,2 stdios this is the same
as `'pipe'`. For any higher value, `'ignore'`
2. `'ignore'` - Open the fd in the child, but do not expose it to the parent
3. `'pipe'` - Open the fd and expose as a `Stream` object to parent.
4. `'ipc'` - Create IPC channel for passing messages/file descriptors between
parent and child.
Note: A ChildProcess may have at most *one* IPC stdio file descriptor.
Setting this option enables the ChildProcess.send() method. If the
child writes JSON messages to this file descriptor, then this will trigger
ChildProcess.on('message'). If the child is a Node.js program, then
the presence of an IPC channel will enable process.send() and
process.on('message')
5. positive integer - Share corresponding fd with child
6. Any TTY, TCP, File stream (or any object with `fd` property) - Share
corresponding stream with child.
As a shorthand, the `stdio` argument may also be one of the following
strings, rather than an array:
* `ignore` - `['ignore', 'ignore', 'ignore']`
* `pipe` - `['pipe', 'pipe', 'pipe']`
* `inherit` - `[process.stdin, process.stdout, process.stderr]` or `[0,1,2]`
Example:
var spawn = require('child_process').spawn;
// Child will use parent's stdios
spawn('prg', [], { stdio: 'inherit' });
// Spawn child sharing only stderr
spawn('prg', [], { stdio: ['pipe', 'pipe', process.stderr] });
// Open an extra fd=4, to interact with programs present a
// startd-style interface.
spawn('prg', [], { stdio: ['pipe', null, null, null, 'pipe'] });
There is a deprecated option called `customFds` which allows one to specify
specific file descriptors for the stdio of the child process. This API was
not portable to all platforms and therefore removed.
@ -354,8 +396,9 @@ See also: `child_process.exec()` and `child_process.fork()`
* `command` {String} The command to run, with space-separated arguments
* `options` {Object}
* `cwd` {String} Current working directory of the child process
* `stdio` {Array|String} Child's stdio configuration. (See above)
* `customFds` {Array} **Deprecated** File descriptors for the child to use
for stdio. (See below)
for stdio. (See above)
* `env` {Object} Environment key-value pairs
* `setsid` {Boolean}
* `encoding` {String} (Default: 'utf8')
@ -411,8 +454,9 @@ the child process is killed.
* `args` {Array} List of string arguments
* `options` {Object}
* `cwd` {String} Current working directory of the child process
* `stdio` {Array|String} Child's stdio configuration. (See above)
* `customFds` {Array} **Deprecated** File descriptors for the child to use
for stdio. (See below)
for stdio. (See above)
* `env` {Object} Environment key-value pairs
* `setsid` {Boolean}
* `encoding` {String} (Default: 'utf8')
@ -436,8 +480,6 @@ leaner than `child_process.exec`. It has the same options.
* `args` {Array} List of string arguments
* `options` {Object}
* `cwd` {String} Current working directory of the child process
* `customFds` {Array} **Deprecated** File descriptors for the child to use
for stdio. (See below)
* `env` {Object} Environment key-value pairs
* `setsid` {Boolean}
* `encoding` {String} (Default: 'utf8')

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