Console I/O (Debugging with GDB)

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#### E.14.6 Console I/O

By default and if not explicitly closed by the target system, the file descriptors 0, 1 and 2 are connected to the GDB console. Output on the GDB console is handled as any other file output operation (`write(1, …)` or `write(2, …)`). Console input is handled by GDB so that after the target read request from file descriptor 0 all following typing is buffered until either one of the following conditions is met:

- The user types `Ctrl-c`. The behaviour is as explained above, and the `read` system call is treated as finished.
- The user presses `RET`. This is treated as end of input with a trailing newline.
- The user types `Ctrl-d`. This is treated as end of input. No trailing character (neither newline nor ‘`Ctrl-D`’) is appended to the input.

If the user has typed more characters than fit in the buffer given to the `read` call, the trailing characters are buffered in GDB until either another `read(0, …)` is requested by the target, or debugging is stopped at the user’s request.