You can always ask the debugger itself for information on its commands, using the command help.
You can use help (abbreviated h) with no arguments to display a short list of named classes of commands:
(gdb) help List of classes of commands: running -- Running the program stack -- Examining the stack data -- Examining data breakpoints -- Making program stop at certain points files -- Specifying and examining files status -- Status inquiries support -- Support facilities user-defined -- User-defined commands aliases -- Aliases of other commands obscure -- Obscure features Type "help" followed by a class name for a list of commands in that class. Type "help" followed by command name for full documentation. Command name abbreviations are allowed if unambiguous. (gdb)
Using one of the general help classes as an argument, you can get a list of the individual commands in that class. For example, here is the help display for the class status:
With a command name as help argument, the debugger displays a short paragraph on how to use that command.
The complete args command lists all the possible completions for the beginning of a command. Use args to specify the beginning of the command you want completed. For example:
This is intended for use by Emacs.
In addition to help, you can use the debugger commands info and show to inquire about the state of your program, or the state of the debugger itself. Each command supports many topics of inquiry; this manual introduces each of them in the appropriate context. The listings under info and under show in the Index point to all the sub-commands.
This command (abbreviated i) is for describing the state of your program. For example, you can list the arguments given to your program with info args, list the registers currently in use with info registers, or list the breakpoints you have set with info breakpoints. You can get a complete list of the info sub-commands with help info.
You can assign the result of an expresson to an environment variable with set. For example, you can set the debugger prompt to a dollar sign with set prompt $.
In contrast to info, show is for describing the state of the debugger itself. You can change most of the things you can show, by using the related command set; for example, you can control what number system is used for displays with set radix, or simply inquire which is currently in use with show radix.
To display all the settable parameters and their current values, you can use show with no arguments; you may also use info set. Both commands produce the same display.
Here are three miscellaneous show subcommands, all of which are exceptional in lacking corresponding set commands:
Show which version of the debugger is running. You should include this information in debugger bug reports. If multiple versions of the debugger are in use at your site, you may occasionally want to determine which version of the debugger you are running; as the debugger evolves, new commands are introduced, and old ones may wither away. The version number is also announced when you start the debugger.
Display information about permission for copying the debugger.
Display the GNU "NO WARRANTY" statement.