2.1 Invoking No value for GDBN

Invoke No value for GDBN by running the program No value for GDBP. Once started, No value for GDBN reads commands from the terminal until you tell it to exit.

You can also run No value for GDBP with a variety of arguments and options, to specify more of your debugging environment at the outset.

The command-line options described here are designed to cover a variety of situations; in some environments, some of these options may effectively be unavailable.

The most usual way to start No value for GDBN is with one argument, specifying an executable program:

No value for GDBP program

You can also start with both an executable program and a core file specified:

No value for GDBP program core

You can, instead, specify a process ID as a second argument, if you want to debug a running process:

No value for GDBP program 1234

would attach No value for GDBN to process 1234 (unless you also have a file named ‘1234’; No value for GDBN does check for a core file first).

Taking advantage of the second command-line argument requires a fairly complete operating system; when you use No value for GDBN as a remote debugger attached to a bare board, there may not be any notion of “process”, and there is often no way to get a core dump. No value for GDBN will warn you if it is unable to attach or to read core dumps.

You can optionally have No value for GDBP pass any arguments after the executable file to the inferior using --args. This option stops option processing.

No value for GDBP --args gcc -O2 -c foo.c

This will cause No value for GDBP to debug gcc, and to set gcc's command-line arguments (see section Your Program's Arguments) to ‘-O2 -c foo.c’.

You can run No value for GDBP without printing the front material, which describes No value for GDBN's non-warranty, by specifying -silent:

No value for GDBP -silent

You can further control how No value for GDBN starts up by using command-line options. No value for GDBN itself can remind you of the options available.

Type

No value for GDBP -help

to display all available options and briefly describe their use (‘No value for GDBP -h’ is a shorter equivalent).

All options and command line arguments you give are processed in sequential order. The order makes a difference when the ‘-x’ option is used.