Fetching the user-agent string from a request using either NodeJS or NodeJS + Express

node-user-agent.js

/** Native NodeJS */
var http = require('http')
  , server = http.createServer(function(req) {
        console.log(req.headers['user-agent']);
    });

server.listen(3000, 'localhost');

/** NodeJS with Express */
var express = require('express')
  , http = require('http')
  , app = express();

http.createServer(app).listen(3000);

app.get('/', function(req, res) {
    console.log(req.get('user-agent'));
});

good job

nice

Thanks

Thank You.

thanks man

Thanks

NestJS way:

import {
    Body,
    Controller,
    Headers,
    Post,
    Request,
    UseGuards,
} from '@nestjs/common';
import { ApiTags } from '@nestjs/swagger';
import { Request as ExpressRequest } from 'express';

import { AuthService } from './auth.service';
import {
    LoginDto,
    GeneratedJwtTokenResponseDto,
} from './dto';
import { LocalAuthGuard } from './local-auth.guard';

@ApiTags('Authentication')
@Controller('auth')
export class AuthController {
    constructor(private readonly authService: AuthService) {}

    @UseGuards(LocalAuthGuard)
    @Post('login')
    async login(
        @Request() req: ExpressRequest,
        @Body() requestBody: LoginDto,
        @Headers('User-Agent') userAgent: string, 
        // @Headers() headers: Record<string, any>, equivalent to req.headers. You can read by: headers['User-Agent']
    ): Promise<GeneratedJwtTokenResponseDto> {
        return await this.authService.login({
            user: req.user as any,
            ip: req.ip,
            userAgent,
        });
    }
}

Thanks guys

Thanks guys!