quartz/content/out/notes/shell.md

title	sr-due	sr-interval	sr-ease
shell	2022-05-22	53	310

tags: #review

---

Shells

• start and stop OS processes
• used to control OS
• connect output of one OS process to input of another process -> this is the idea of Unix pipes
• manage environment variables: pass params to programs
• parse and evaluate command line instructions from user