lib/exec.js

// Copyright (c) 2012-2017, Matt Godbolt
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

var child_process = require('child_process'),
    logger = require('./logger').logger;


function execute(command, args, options) {
    options = options || {};
    var maxOutput = options.maxOutput || 1024 * 1024;
    var timeoutMs = options.timeoutMs || 0;
    var env = options.env;

    if (options.wrapper) {
        args.unshift(command);
        command = options.wrapper;
    }

    var okToCache = true;
    logger.debug({type: "executing", command: command, args: args});
    var child = child_process.spawn(command, args, {
        env: env,
        detached: process.platform == 'linux'
    });
    var stderr = "";
    var stdout = "";
    var timeout;
    if (timeoutMs)
        timeout = setTimeout(function () {
            okToCache = false;
            child.kill();
            stderr += "\nKilled - processing time exceeded";
        }, timeoutMs);
    var truncated = false;
    child.stdout.on('data', function (data) {
        if (truncated) return;
        if (stdout.length > maxOutput) {
            stdout += "\n[Truncated]";
            truncated = true;
            child.kill();
            return;
        }
        stdout += data;
    });
    child.stderr.on('data', function (data) {
        if (truncated) return;
        if (stderr.length > maxOutput) {
            stderr += "\n[Truncated]";
            truncated = true;
            child.kill();
            return;
        }
        stderr += data;
    });
    child.on('exit', function (code) {
        logger.debug({type: 'exited', code: code});
        if (timeout !== undefined) clearTimeout(timeout);
    });
    return new Promise(function (resolve, reject) {
        child.on('error', function (e) {
            logger.debug("Error with " + command + " args", args, ":", e);
            reject(e);
        });
        child.on('close', function (code) {
            if (timeout !== undefined) clearTimeout(timeout);
            var result = {
                code: code,
                stdout: stdout,
                stderr: stderr,
                okToCache: okToCache
            };
            logger.debug({type: "executed", command: command, args: args, result: result});
            resolve(result);
        });
        if (options.input) child.stdin.write(options.input);
        child.stdin.end();
    });
}

exports = {
    execute: execute
};