Linux Guides

Introduction to Linux on Pegasus

Pegasus is currently running the CentOS 7.6 operating system, a distribution of Linux. Linux is a UNIX-like kernel, though in this document it will generally refer to the entire CentOS distribution. The three basic components of UNIX-like operating systems are the kernel, shell, and system programs. The kernel handles resource management and program execution. The shell interprets user commands typed at a prompt. System programs implement most operating system functionalities such as user environments and schedulers.

Everything in Linux is either a file (a collection of data) or a process (an executing program). Directories in Linux are types of files.

In the below examples, username represents your access account.

Linux FAQs

How can I check my shell?

$ echo $SHELL or $ echo $0

How can I view my environment variables?

$ env or $ env | sort

How can I check command/software availability and location?

$ which executable, for example $ which vim

How can I get help with commands/software?

Use the Linux manual pages: $ man executable, for example $ man vim