Introduction to Using the Shell in a High-Performance Computing Context: Glossary

High Performance Computing (HPC) typically involves connecting to very large computing systems elsewhere in the world.

These HPC systems can be used to do work that would either be impossible or much slower or smaller systems.

The standard method of interacting with such systems is via a command line interface such as Bash.

To connect to a remote HPC system using SSH: ssh yourUsername@remote.computer.address

Your current directory is referred to as the working directory.

To change directories, use cd.

To view files, use ls.

You can view help for a command with man command or command --help.

Hit tab to autocomplete whatever you’re currently typing.

Use nano to create or edit text files from a terminal.

cat file1 [file2 ...] prints the contents of one or more files to terminal.

mv old dir moves a file or directory to another directory dir.

mv old new renames a file or directory.

cp old new copies a file.

cp old dir copies a file to another directory dir.

rm path deletes (removes) a file.

File extensions are entirely arbitrary on UNIX systems.

The * wildcard is used as a placeholder to match any text that follows a pattern.

Redirect a command’s output to a file with >.

Commands can be chained with |

A shell script is just a list of bash commands in a text file.

chmod +x script.sh will give it permission to execute.