More linux helpful commands

Find a string in any file in a directory

grep -ri “searchstring”

Find a file

find <path> -name *FileName*

Case Insensitive Search

find /path/to/search -iname '*.txt'

 RegEx File Name (either pipe to grep or use regex from find .)

 find | grep "*.txt"

find . -regex 'f[[:test:]]\.txt'

Or another way to find Recursively

tree -f | grep filename

Find where a command is located and the history of commands

which file , which which
history --> will show you all recent commands

Find some text in a file – e.g find ‘error’ in apache access_log

sudo cat /var/log/httpd/access_log |  grep error

sudo cat /var/log/httpd/error_log |  grep error

Reset the hostname on a linux host

sudo hostnamectl set-hostname mywebsite.com

Check OS version

lsb_release -a

On rhel - cat /etc/redhat-release

Check whether firewall port is open

grep -w '443/tcp' /etc/services

Check what my proxy server is

env | grep proxy

echo $http_proxy