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.
- Navigating the Linux Shell
- Interacting with Files on Pegasus
- Make directories with
mkdir
: - Remove directories with
rmdir
: - Remove files and directories with
rm
: - View file contents with
cat
: - Create files with
cat
and redirection: - View file contents with
head
andtail
: - Rename and Move with
mv
: - Copy with
cp
: - Edit files :
nano
,emacs
,vi
: - View file contents by page with
more
andless
:
- Make directories with
- File Permissions in Linux
- Access Control Lists – ACL
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