Stream Redirection

Core Idea

Commands have stdin, stdout, and stderr. Redirection sends those streams somewhere else.

Practice Alone

Save stdout to a file, save stderr to a different file, then combine them into one log.

Done When

You choose >, >>, 2>, 2>&1, and /dev/null deliberately.

Go Deeper

• I/O explains stdin, stdout, and stderr.
• File descriptors explains why stderr is descriptor 2.
• Devices and /dev/null explain discarded output.
• One-liners explains grouped commands with one redirection.
• Shell explains how Bash sets up redirection before starting a command.