【Node】fs

var fs = require('fs') // fs 文件系统
var stdin = process.stdin
var stdout = process.stdout
var stats = []

fs.readdir(process.cwd(), function(err, files) {
    console.log('')
    if (!files.length) {
        return console.log('    03[31m No files to show!03[39
')
    }
    console.log('    Select which file or directory you want to see
')

    function file(i) {
        var filename = files[i]
        fs.stat(__dirname + '/' + filename, function(err, stat) { // fs.stat会给出文件或目录的元数据
            stats[i] = stat
            if (stat.isDirectory()) {
                console.log('    '+i+'    33[36m' + filename + '/33[39m')
            } else {
                console.log('    '+i+'    33[90m' + filename + '/33[39m')
            }
            if (++i == files.length) {
                read()
            } else {
                file(i)
            }
        })
    }
    function read() {
        console.log('')
        stdout.write('    33[33mEnter you choice: 33[39m')
        stdin.resume()
        stdin.setEncoding('utf-8')
        stdin.on('data', option)
    }

    function option(data) {
        var filename = files[Number(data)]
        if (!filename) {
            stdout.write('   33[31mEnter your choice: 33[39m')
        } else {
            stdin.pause()
            if (stats[Number(data)].isDirectory()) {
                fs.readdir(__dirname + '/' + filename, function(err, files) {
                    console.log('')
                    console.log('    (' + files.length + ' files)')
                    files.forEach(function(file) {
                        console.log('    -    ' + file)
                    })
                    console.log('')
                })
            } else {
                fs.readFile(__dirname + '/' + filename, 'utf-8', function(err, data) {
                    console.log('')
                    console.log('33[90m' + data.replace(/(.*)/g, '    $1') + '33[39m')
                })
            }
        }
    }

    file(0)
})

console.log('Hello world')
process.stdout.write('Hello world')
console.log('Hello world')

console.log内部做了这样的事情：它在指定的字符串后加上 （换行）字符，并将其写到stdout流中