Networking
curl it is a tool to transfer data from and to a server using one of the supported protocol
whois google.com #Whois is an easy way to find information on the owner, nameserver, registrar etc. of a domain name.
ping google.com # ping will check if you can actually reach the server or not
curl http://example.com
curl example.com
curl -I -l -k or -Ilk example.com
curl -l -v -k or -Ivk example.com
-I Include the HTTP-header in the output. it includes things like server name, date of doc, HTTP-version
-k --insecure By default every connection curl makeis verfied to be secure
-l --list-only
-v --verbose
traceroute google.com #journey of packet from source to destination
dig google.com #this is the command to querying the domain name system
dig google.com any # to query any type of the record
dig +trace www.example.com
nslookup -type=SRV tesdfasfdafaf.local. #nslookup is also used for querying domain name system to obtain doamin name or public ip assocaited with that record
dig and host If you want to check that your DNS servers are being queried properly, you can use the host or dig
dig google.com
host google.com
view the content of /etc/bashrc to find the setting of the command prompt edit bashrc to make changes to the command prompt
/etc/profile /etc/bashrc ~/.bashrc
Packages yum
yum list installed | grep -i httpd24
grep #content of file single file or whole directory structure
grep PS1
grep -r PS1 . or grep -r PS1 /etc/
grep PS1 .bashrc
grep -i ****** #case insensitive
grep -l ****** #return file name instead of content
grep -nwr 'text-to-search' file-path (. for current directory) # n - line number w - match whole word r - recursive search
Find #find by file name
find ~/locationtofind -name 'name' # -iname for exact search
-type f #for search only files
-type d #for search only directories
find ~/deployment-data-code/ -name test.config -exec grep "yum" '{}' \; -print
find . -type f -print | xargs grep "example"
find . -name "*.bak" -delete
Locate
locate pwd # it will give all the place wher it is stored
Storage
df -h
sudo du -csh # disk usage on linux
User
adduser test #add new user test
passwd test #add password for new user test