index.js

var type = {
    connected: /^(\S+) connected (?:(\d+)x(\d+)\+(\d+)\+(\d))*\s*(\(\w+\))*\s*(\w*)/,
    disconnected: /^(\S+) disconnected/,
    mode: /^\s+(\d+)x([0-9i]+)\s+(\(\w+\))\s+([0-9]+\.[0-9]+)MHz\s+((\s*[\+]*[\-]*\w*\s)*)/,
    dimension_horizontal: /^\s+h\:\s+width\s+(\d+)\s+start\s+(\d+)\s+end\s+(\d+)\s+total\s+(\d+)\s*skew\s*(\w)\s*clock\s*([0-9]*.[0-9]*)/,
    dimension_vertical: /^\s+v\:\s+height\s+(\d+)\s+start\s+(\d+)\s+end\s+(\d+)\s+total\s+(\d+)\s*clock\s*([0-9]*.[0-9]*)/
};


/**
 * This function parses an xrandr output with the following format
 * Screen 0: minimum 320 x 200, current 1080 x 1920, maximum 2048 x 2048
 * HDMI-1 connected 1080x1920+0+0 (0x44) right (normal left inverted right x axis y axis) 477mm x 268mm
 * 	Identifier: 0x42
 * 	Timestamp:  96798461
 * 	Subpixel:   unknown
 * 	Gamma:      1.0:1.0:1.0
 * 	Brightness: 1.0
 * 	Clones:    
 * 	CRTC:       2
 * 	CRTCs:      2
 * 	Transform:  1.000000 0.000000 0.000000
 * 	            0.000000 1.000000 0.000000
 * 	            0.000000 0.000000 1.000000
 * 	           filter: 
 * 	EDID: 
 * 		00ffffffffffff001e6dd75801010101		
 *   1920x1080 (0x44) 148.500MHz +HSync +VSync *current +preferred
 *         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
 *         v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
 *   1920x1080 (0x45) 148.500MHz +HSync +VSync
 *         h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
 *         v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz 
 * 
 * @param {*} data
 */
module.exports = function (data) {
    var lines = data.split('\n');
    var result = {};
    var last_connection = null;
    var last_mode = 0;
    var index = 0;

    lines.forEach(function (line) {
            var tmp;
            if ((tmp = type.connected.exec(line))) {
                if (tmp[3] !== undefined) {
                    result[tmp[1]] = {
                        connected: true,
                        orientation: tmp[7],
                        modes: [],
                        index: index++
                    };
                    if (tmp[2] && tmp[3]) {
                        result[tmp[1]].width = parseInt(tmp[2]);
                        result[tmp[1]].height = parseInt(tmp[3]);
                    }
                    if (tmp[4] && tmp[5]) {
                        result[tmp[1]].left = parseInt(tmp[4]);
                        result[tmp[1]].top = parseInt(tmp[5]);
                    }
                    last_connection = tmp[1];
                } else {
                    result[tmp[1]] = {
                        connected: false,
                        orientation: null,
                        modes: [],
                        index: index++,
                        width: 0,
                        height: 0,
                        top: 0,
                        left: 0
                    };
                    last_connection = tmp[1];

                }

            } else if ((tmp = type.disconnected.exec(line))) {
                result[tmp[1]] = {
                    connected: false,
                    modes: [],
                    index: index++
                };
                last_connection = tmp[1];
            } else if ((tmp = type.mode.exec(line))) {
                var dimensions = {
                    vertical: null,
                    horizontal: null
                };
                var r = {
                    name: tmp[1] + 'x' + tmp[2],
                    width: tmp[1],
                    height: tmp[2],
                    rate: parseFloat(tmp[4]),
                    optionals: tmp[5],
                    current: line.includes('current') ? true : false,
                    preferred: line.includes('preferred') ? true : false,
                    dimensions: dimensions
                };
                result[last_connection].modes.push(r);
                last_mode++;
            } else if ((tmp = type.dimension_horizontal.exec(line))) {
                var dimension_h = {
                    width: tmp[1],
                    start: tmp[2],
                    end: tmp[3],
                    total: tmp[4],
                    skew: tmp[5],
                    clock: parseFloat(tmp[6])
                };
                result[last_connection].modes[last_mode - 1].dimensions.horizontal = dimension_h;

            } else if ((tmp = type.dimension_vertical.exec(line))) {
                var dimension_v = {
                    width: tmp[1],
                    start: tmp[2],
                    end: tmp[3],
                    total: tmp[4],
                    clock: parseFloat(tmp[5])

                };
                result[last_connection].modes[last_mode - 1].dimensions.vertical = dimension_v;
            }
        });
    return result;
};