Top Interview Questions and Answers in Linux: Part-1
Hello everyone, In this article, we will mostly talk about top interview questions and answers in Linux. Along with that will go through some examples also. I will create a series of questions and answers for beginners to advanced levels.
Check Linux Kernal Version
- uname -a
- uname -v
- uname -r
Verify current IP address in linux
- ifconfig
- ip addr show eth0
Free disk space
df -ah (h is used for human readable format)
How to verify manage services in linux?
Verifying service status:
- service {service_name} status
- systemctl status {service_name} // new one
for ex: systemctl status nginx
Start a specific service:
- service {service_name} start
- systemctl start {service_name}
for ex: systemctl start nginx
Stop a specific service:
- service {service_name} stop
- systemctl stop {service_name}
for ex: systemctl stop nginx
Restart a specific service:
- service {service_name}restart
- systemctl restart {service_name}
for ex: systemctl restart nginx
Size of directory
du -sh {directory_name}
How to open ports in linux?
netstat -tulpn
Verify CPU usage process
ps aux | grep {process_name}
for ex: ps aux | grep apache2
Deal with mount
ls /mnt
mount /dev/sda2 /mnt
mount
Getting manual of any command
man {command}
Finding mount filesystem
findmnt /mnt
Unmount filesystem
sudo unmount /mnt
Manipulating data and generates reports
- awk '{print}' {file_name}
- awk '/manager/{print}' {file_name}
- awk '{print} $1,$2' {file_name}
- awk 'if($3=="B6") print $0;' {file_name}
- awk 'BEGIN{for(i=1;i<=6;i++) print "squareof"', i; "is", i*i;}'
Stream editor
- sed 's/unix/linux/' {file_name}
- sed 's/unix/linux/2' {file_name}
- sed 's/unix/linux/g' {file_name}
- sed 's/unix/linux/3g' {file_name}
- sed '3 s/unix/linux/' {file_name}