Shell condition test statement, string test whether apache is enabled

It takes me 10 minutes to understand "! = The difference between "-n" and "-n". Take a note and complete it.

 

Method 1: Test whether apache is enabled? String Testing

#! /Bin/bash

Web = '/usr/bin/pgrep httpd'

If [-n "$ web"]; // whether the returned web value is null

Then

Echo "httpd is running"

Else

/Etc/init. d/httpd start

Fi

Second:

#! /Bin/bash

Web = '/usr/bin/pgrep httpd'

If ["$ web "! = ""]; // Whether the web return value is null

Then

Echo "httpd is running"

Else

/Etc/init. d/httpd start

Fi