RTEMS GNU Tools On-Line Library

Mode Options

Debugging with GDB

2.1.2: Choosing modes

You can run GDB in various alternative modes---for example, in batch mode or quiet mode.

-nx

-n

Do not execute commands found in any initialization files (normally called `.gdbinit', or `gdb.ini' on PCs). Normally, GDB executes the commands in these files after all the command options and arguments have been processed. See Command Files.

-quiet

-silent

-q

``Quiet''. Do not print the introductory and copyright messages. These messages are also suppressed in batch mode.

-batch

Run in batch mode. Exit with status 0 after processing all the command files specified with `-x' (and all commands from initialization files, if not inhibited with `-n'). Exit with nonzero status if an error occurs in executing the GDB commands in the command files.

Batch mode may be useful for running GDB as a filter, for example to download and run a program on another computer; in order to make this more useful, the message

Program exited normally.

(which is ordinarily issued whenever a program running under GDB control terminates) is not issued when running in batch mode.

-nowindows

-nw

``No windows''. If GDB comes with a graphical user interface (GUI) built in, then this option tells GDB to only use the command-line interface. If no GUI is available, this option has no effect.

-windows

-w

If GDB includes a GUI, then this option requires it to be used if possible.

-cd directory

Run GDB using directory as its working directory, instead of the current directory.

-fullname

-f

GNU Emacs sets this option when it runs GDB as a subprocess. It tells GDB to output the full file name and line number in a standard, recognizable fashion each time a stack frame is displayed (which includes each time your program stops). This recognizable format looks like two `\032' characters, followed by the file name, line number and character position separated by colons, and a newline. The Emacs-to-GDB interface program uses the two `\032' characters as a signal to display the source code for the frame.

-epoch

The Epoch Emacs-GDB interface sets this option when it runs GDB as a subprocess. It tells GDB to modify its print routines so as to allow Epoch to display values of expressions in a separate window.

-annotate level

This option sets the annotation level inside GDB. Its effect is identical to using `set annotate level' (see Annotations). Annotation level controls how much information does GDB print together with its prompt, values of expressions, source lines, and other types of output. Level 0 is the normal, level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 2 is the maximum annotation suitable for programs that control GDB.

-async

Use the asynchronous event loop for the command-line interface. GDB processes all events, such as user keyboard input, via a special event loop. This allows GDB to accept and process user commands in parallel with the debugged process being run[1], so you don't need to wait for control to return to GDB before you type the next command. (Note: as of version 5.0, the target side of the asynchronous operation is not yet in place, so `-async' does not work fully yet.)

When the standard input is connected to a terminal device, GDB uses the asynchronous event loop by default, unless disabled by the `-noasync' option.

-noasync

Disable the asynchronous event loop for the command-line interface.

-baud bps

-b bps

Set the line speed (baud rate or bits per second) of any serial interface used by GDB for remote debugging.

-tty device

-t device

Run using device for your program's standard input and output.

-interpreter interp

Use the interpreter interp for interface with the controlling program or device. This option is meant to be set by programs which communicate with GDB using it as a back end. For example, `--interpreter=mi' causes GDB to use the gdbmi interface (see GDB/MI).

-write

Open the executable and core files for both reading and writing. This is equivalent to the `set write on' command inside GDB (see Patching).

-statistics

This option causes GDB to print statistics about time and memory usage after it completes each command and returns to the prompt.

-version

This option causes GDB to print its version number and no-warranty blurb, and exit.

[1] GDB built with DJGPP tools for MS-DOS/MS-Windows supports this mode of operation, but the event loop is suspended when the debuggee runs.

Debugging with GDB