I'm making this page because every single time I Google for "How to do X in Bash", I literally get a crappy page with ads that doesn't actually answer my question. So, maybe this page will answer this for me and for others.
How do I redirect stdout to a file?
command > filename
How do I redirect stderr to a file?
command 2>filename
How do I redirect both to a file?
# supported by all shells
command > filename 2>&1
# supported only by bash and zsh
command &> filename