Every Linux process is born with three open channels: stdin (file descriptor 0 — keyboard input), stdout (fd 1 — normal output), and stderr (fd 2 — error messages). By default all three are connected to your terminal. I/O redirection lets you rewire those channels so output goes to a file instead of the screen, errors go to a separate log, or one command's output feeds directly into another command's input. Mastering redirection means you can capture output, suppress noise, chain tools together, and build powerful one-liners — all critical RHCSA skills.
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