3.3 Getting Help

You can always ask No value for GDBN itself for information on its commands, using the command help.

help

h

You can use help (abbreviated h) with no arguments to display a short list of named classes of commands:

(No value for GDBP) help List of classes of commands: aliases -- Aliases of other commands breakpoints -- Making program stop at certain points data -- Examining data files -- Specifying and examining files internals -- Maintenance commands obscure -- Obscure features running -- Running the program stack -- Examining the stack status -- Status inquiries support -- Support facilities tracepoints -- Tracing of program execution without stopping the program user-defined -- User-defined commands 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. (No value for GDBP)

help class

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:

(No value for GDBP) help status Status inquiries. List of commands: info -- Generic command for showing things about the program being debugged show -- Generic command for showing things about the debugger Type "help" followed by command name for full documentation. Command name abbreviations are allowed if unambiguous. (No value for GDBP)

help command

With a command name as help argument, No value for GDBN displays a short paragraph on how to use that command.

apropos args

The apropos command searches through all of the No value for GDBN commands, and their documentation, for the regular expression specified in args. It prints out all matches found. For example:

apropos reload

results in:

set symbol-reloading -- Set dynamic symbol table reloading multiple times in one run show symbol-reloading -- Show dynamic symbol table reloading multiple times in one run

complete args

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:

complete i

results in:

if ignore info inspect

This is intended for use by GNU Emacs.

In addition to help, you can use the No value for GDBN commands info and show to inquire about the state of your program, or the state of No value for GDBN 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. See section Index.

info

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.

set

You can assign the result of an expression to an environment variable with set. For example, you can set the No value for GDBN prompt to a $-sign with set prompt $.

show

In contrast to info, show is for describing the state of No value for GDBN 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 version

Show what version of No value for GDBN is running. You should include this information in No value for GDBN bug-reports. If multiple versions of No value for GDBN are in use at your site, you may need to determine which version of No value for GDBN you are running; as No value for GDBN evolves, new commands are introduced, and old ones may wither away. Also, many system vendors ship variant versions of No value for GDBN, and there are variant versions of No value for GDBN in GNU/Linux distributions as well. The version number is the same as the one announced when you start No value for GDBN.

show copying

info copying

Display information about permission for copying No value for GDBN.

show warranty

info warranty

Display the GNU “NO WARRANTY” statement, or a warranty, if your version of No value for GDBN comes with one.