10 Must Know Linux Admin Commands

We bring you certain essential Linux commands that are important for you as a developer. 

As stated on jpgtutorials.com, this tutorial is been based on Ubuntu 8.04.2. Putty. Please see cited below the Linux commands 

• cat /etc/issue - This will inform you about the Linux distribution and versions and is especially useful with so many distributions available like RedHat, Debian, Ubuntu etc.

• ifconfig - This is used by everybody to know the IP address of the system along with other network related information. The inet addr key speaks about IP address and the command resides in /sbin. If this is not in path, you have to execute /sbin/ifconfig command to get there.

• ps - This will give you information about currently running processes in Linux system. ps -e shows all processes as every process in Linux is identified by a unique identification number. Processes may have parent process id where each process originated. For optional information about parent process just type ps –ef and hit enter.

• kill - This is to stop a process immediately. It works with ps command where you get process id. The syntax of kill command is give as follows. kill . Just a word of caution, if you kill parent process, all child processes are killed.

• free - This shows detailed memory usage, free memory available, memory used for buffering, caching etc and information about swap space. Swap space is disk area allocated for memory usage in case memory requirement exceeds RAM.

• df - This is used to show information regarding available disk space. It prints information regarding mount point, used disk apace, remaining space etc. Type df -m in the command prompt and hit enter. -m attribute shows space in MB.

• top - If your system runs out of memory or show slow responses, you can investigate which process is taking too much memory and CPU. And this command helps you in that. Once top window is running, you may execute interactive commands.

• tar - As a developer, you may face situations where you need to install applications on your Linux system. As almost all installers are packaged as compressed archive files, tar helps you to decompress and compress archive files and extract the files to mysql directory.

• scp - With multiple Linux systems in your network, when you want to copy some files from one host to another. scp command helps you achieve this. This copies file from current system to another system.

• chown - This will change the ownership of files and directories in Linux system. If you want to allow full access to a directory for another user, you can use this command.