Stdin Stdout Stderr
https://www.linuxscrew.com/redirect-stdin-stdout-stderr-bash#Yeah_But_What_Does_that_Actually_Mean (opens in a new tab) https://effective-shell.com/ (opens in a new tab)
Standard Stream
| id | name | default |
|---|---|---|
| 0 | stdin | keyboard |
| 1 | stdout | monitor |
| 2 | stderr | monitor |
Redirection (>, >>, <)
Redirects file echo < input.txt > output.txt
Redirects error cat nofile.txt 2> error.txt
Pipe (|)
Same as redirection, but only deals with stdin/stdout.