#! /usr/bin/env node
'use-strict'

const process = require('process');
const fs = require('fs');

try {
    if (process.argv.length === 3) {
        const stdin = process.openStdin();
        const func = (x) => {
            const str = x.toString('utf-8');
            if (-1 !== str.indexOf(process.argv[2])) {
                process.stdout.write(str);
            }
        };
        stdin.addListener('data', func);
    }
    if (process.argv.length === 4) {
        const exp = process.argv[2];
        const file = fs.readFileSync(process.argv[3], 'utf8');
        let pos = 0;
        let cur = '';
        while (pos < file.length) {
            cur = '';
            while (pos !== -1 && file[pos] !== '\n') {
                cur += file[pos];
                pos++;
            }
            pos++;
            if (-1 !== cur.indexOf(exp)) {
                console.log(cur);
            }
        }
    }
    if (process.argv.length === 5) {
        if (process.argv[2] === '-i') {
            const exp = process.argv[3];
            const file = fs.readFileSync(process.argv[4], 'utf8');
            let pos = 0;
            let cur = '';
            while (pos < file.length) {
                cur = '';
                while (pos !== -1 && file[pos] !== '\n') {
                    cur += file[pos];
                    pos++;
                }
                pos++;
                if (-1 !== cur.toUpperCase().indexOf(exp.toUpperCase())) {
                    console.log(cur);
                }
            }
        }
        if (process.argv[2] === '-n') {
            const exp = process.argv[3];
            const file = fs.readFileSync(process.argv[4], 'utf8');
            let pos = 0;
            let cur = '';
            let now = 1;
            while (pos < file.length) {
                cur = '';
                while (pos !== -1 && file[pos] !== '\n') {
                    cur += file[pos];
                    pos++;
                }
                pos++;
                if (-1 !== cur.indexOf(exp)) {
                    console.log(now + ':' + cur);
                }
                now++;
            }
        }
        if (process.argv[2] === '-e') {
            const exp = process.argv[3];
            const file = fs.readFileSync(process.argv[4], 'utf8');
            file.search(new RegExp(exp));
        }
    }
    if (process.argv.length === 6) {
        if (process.argv[2] === '-m') {
            const lim = process.argv[3];
            const exp = process.argv[4];
            const file = fs.readFileSync(process.argv[5], 'utf8');
            let pos = 0;
            let cur = '';
            let count = 0;
            while (pos < file.length) {
                if (count >= lim) break;
                cur = '';
                while (pos !== -1 && file[pos] !== '\n') {
                    cur += file[pos];
                    pos++;
                }
                pos++;
                if (-1 !== cur.indexOf(exp)) {
                    console.log(cur);
                    count++;
                }
            }
        }
    }
} catch (e) {
    console.error(e.message);
}