From: Fedor Indutny Date: Wed, 16 May 2012 16:04:24 +0000 (+0700) Subject: child_process: new stdio API for .spawn() method X-Git-Tag: v0.7.10~52 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0262b6d2a563e8b96f02c3066b69fed66d956675;p=platform%2Fupstream%2Fnodejs.git child_process: new stdio API for .spawn() method --- diff --git a/doc/api/child_process.markdown b/doc/api/child_process.markdown index 18be2f6..e9aab64 100644 --- a/doc/api/child_process.markdown +++ b/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')