52 lines
1.3 KiB
JavaScript
52 lines
1.3 KiB
JavaScript
var MOVE_LEFT = new Buffer('1b5b3130303044', 'hex').toString();
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var MOVE_UP = new Buffer('1b5b3141', 'hex').toString();
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var CLEAR_LINE = new Buffer('1b5b304b', 'hex').toString();
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var stringWidth = require('string-width');
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module.exports = function(stream) {
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var write = stream.write;
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var str;
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stream.write = function(data) {
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if (str && data !== str) str = null;
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return write.apply(this, arguments);
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};
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if (stream === process.stderr || stream === process.stdout) {
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process.on('exit', function() {
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if (str !== null) stream.write('');
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});
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}
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var prevLineCount = 0;
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var log = function() {
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str = '';
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var nextStr = Array.prototype.join.call(arguments, ' ');
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// Clear screen
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for (var i=0; i<prevLineCount; i++) {
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str += MOVE_LEFT + CLEAR_LINE + (i < prevLineCount-1 ? MOVE_UP : '');
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}
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// Actual log output
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str += nextStr;
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stream.write(str);
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// How many lines to remove on next clear screen
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var prevLines = nextStr.split('\n');
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prevLineCount = 0;
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for (var i=0; i < prevLines.length; i++) {
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prevLineCount += Math.ceil(stringWidth(prevLines[i]) / stream.columns) || 1;
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}
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};
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log.clear = function() {
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stream.write('');
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};
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return log;
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};
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module.exports.stdout = module.exports(process.stdout);
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module.exports.stderr = module.exports(process.stderr);
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