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Diffstat (limited to 'toolkit/modules/subprocess/Subprocess.jsm')
| -rw-r--r-- | toolkit/modules/subprocess/Subprocess.jsm | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/toolkit/modules/subprocess/Subprocess.jsm b/toolkit/modules/subprocess/Subprocess.jsm new file mode 100644 index 000000000..6d0d27d77 --- /dev/null +++ b/toolkit/modules/subprocess/Subprocess.jsm @@ -0,0 +1,163 @@ +/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */ +/* vim: set sts=2 sw=2 et tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* + * These modules are loosely based on the subprocess.jsm module created + * by Jan Gerber and Patrick Brunschwig, though the implementation + * differs drastically. + */ + +"use strict"; + +let EXPORTED_SYMBOLS = ["Subprocess"]; + +/* exported Subprocess */ + +var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components; + +Cu.import("resource://gre/modules/AppConstants.jsm"); +Cu.import("resource://gre/modules/XPCOMUtils.jsm"); +Cu.import("resource://gre/modules/subprocess/subprocess_common.jsm"); + +if (AppConstants.platform == "win") { + XPCOMUtils.defineLazyModuleGetter(this, "SubprocessImpl", + "resource://gre/modules/subprocess/subprocess_win.jsm"); +} else { + XPCOMUtils.defineLazyModuleGetter(this, "SubprocessImpl", + "resource://gre/modules/subprocess/subprocess_unix.jsm"); +} + +/** + * Allows for creation of and communication with OS-level sub-processes. + * @namespace + */ +var Subprocess = { + /** + * Launches a process, and returns a handle to it. + * + * @param {object} options + * An object describing the process to launch. + * + * @param {string} options.command + * The full path of the execuable to launch. Relative paths are not + * accepted, and `$PATH` is not searched. + * + * If a path search is necessary, the {@link Subprocess.pathSearch} method may + * be used to map a bare executable name to a full path. + * + * @param {string[]} [options.arguments] + * A list of strings to pass as arguments to the process. + * + * @param {object} [options.environment] + * An object containing a key and value for each environment variable + * to pass to the process. Only the object's own, enumerable properties + * are added to the environment. + * + * @param {boolean} [options.environmentAppend] + * If true, append the environment variables passed in `environment` to + * the existing set of environment variables. Otherwise, the values in + * 'environment' constitute the entire set of environment variables + * passed to the new process. + * + * @param {string} [options.stderr] + * Defines how the process's stderr output is handled. One of: + * + * - `"ignore"`: (default) The process's standard error is not redirected. + * - `"stdout"`: The process's stderr is merged with its stdout. + * - `"pipe"`: The process's stderr is redirected to a pipe, which can be read + * from via its `stderr` property. + * + * @param {string} [options.workdir] + * The working directory in which to launch the new process. + * + * @returns {Promise<Process>} + * + * @rejects {Error} + * May be rejected with an Error object if the process can not be + * launched. The object will include an `errorCode` property with + * one of the following values if it was rejected for the + * corresponding reason: + * + * - Subprocess.ERROR_BAD_EXECUTABLE: The given command could not + * be found, or the file that it references is not executable. + * + * Note that if the process is successfully launched, but exits with + * a non-zero exit code, the promise will still resolve successfully. + */ + call(options) { + options = Object.assign({}, options); + + options.stderr = options.stderr || "ignore"; + options.workdir = options.workdir || null; + + let environment = {}; + if (!options.environment || options.environmentAppend) { + environment = this.getEnvironment(); + } + + if (options.environment) { + Object.assign(environment, options.environment); + } + + options.environment = Object.keys(environment) + .map(key => `${key}=${environment[key]}`); + + options.arguments = Array.from(options.arguments || []); + + return Promise.resolve(SubprocessImpl.isExecutableFile(options.command)).then(isExecutable => { + if (!isExecutable) { + let error = new Error(`File at path "${options.command}" does not exist, or is not executable`); + error.errorCode = SubprocessConstants.ERROR_BAD_EXECUTABLE; + throw error; + } + + options.arguments.unshift(options.command); + + return SubprocessImpl.call(options); + }); + }, + + /** + * Returns an object with a key-value pair for every variable in the process's + * current environment. + * + * @returns {object} + */ + getEnvironment() { + let environment = Object.create(null); + for (let [k, v] of SubprocessImpl.getEnvironment()) { + environment[k] = v; + } + return environment; + }, + + /** + * Searches for the given executable file in the system executable + * file paths as specified by the PATH environment variable. + * + * On Windows, if the unadorned filename cannot be found, the + * extensions in the semicolon-separated list in the PATHSEP + * environment variable are successively appended to the original + * name and searched for in turn. + * + * @param {string} command + * The name of the executable to find. + * @param {object} [environment] + * An object containing a key for each environment variable to be used + * in the search. If not provided, full the current process environment + * is used. + * @returns {Promise<string>} + */ + pathSearch(command, environment = this.getEnvironment()) { + // Promise.resolve lets us get around returning one of the Promise.jsm + // pseudo-promises returned by Task.jsm. + let path = SubprocessImpl.pathSearch(command, environment); + return Promise.resolve(path); + }, +}; + +Object.assign(Subprocess, SubprocessConstants); +Object.freeze(Subprocess); |