ng serve not detecting file changes automatically

Issue

I need to run ng serve every time when any changes made to the source files.I have no error in the console.

Angular CLI: 1.6.2
Node: 8.9.1
OS: linux ia32
Angular: 5.1.2
... animations, common, compiler, compiler-cli, core, forms
... http, language-service, platform-browser
... platform-browser-dynamic, router

@angular/cdk: 5.0.2-c3d7cd9
@angular/cli: 1.6.2
@angular/material: 5.0.3-e20d8f0
@angular-devkit/build-optimizer: 0.0.36
@angular-devkit/core: 0.0.22
@angular-devkit/schematics: 0.0.42
@ngtools/json-schema: 1.1.0
@ngtools/webpack: 1.9.2
@schematics/angular: 0.1.11
@schematics/schematics: 0.0.11
typescript: 2.4.2
webpack: 3.10.0

Solution

Most of the times in Linux, ng serve or ng build --watch doesn't work if the directory doesn't have sufficient permissions.

The solution is either to provide the necessary permissions or to use sudo instead.

UPDATE

watch flag in ng serve is actually redundant as it is the default option. Credit to @Zaphoid for pointing out the mistake.

Answered By - planet_hunter