Editing Dd (Unix) (section)

=== Output messages ===
On completion, {{code|dd}} writes statistics to [[Standard streams#Standard error (stderr)|standard error]]. The format is standardized in POSIX.<ref name=SUS/>{{rp|at=STDERR}} The manual page for GNU dd does not describe this format, but the BSD manuals do. Each of the "Records in" and "Records out" lines shows the number of complete blocks transferred + the number of partial blocks, e.g. because the physical medium ended before a complete block was read, or a physical error prevented reading the complete block.

If {{code|dd}} receives a [[SIGINFO]] signal while it's running {{endash}} typically triggered by the user pressing {{key|Ctrl|T}} {{endash}} it writes intermediate statistics to standard error and continues processing.