60 lines
1.3 KiB
JavaScript
60 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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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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write.apply(this, arguments);
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};
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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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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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prevLineCount = nextStr.split('\n').length;
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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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if (require.main !== module) return;
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var log = module.exports.stdout;
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var i=0;
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setInterval(function() {
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i++;
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var s = 'line 1 - '+Math.random();
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if (i < 10) s += ' - '+Math.random();
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s += '\nline 2 - '+Math.random();
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if (i<20) s += '\nline 3 - '+Math.random()+'\nline 4 - '+Math.random();
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log(s);
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}, 200);
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