Variables

The following read-only predefined variables represent the current state of dbx. They are always valid. They follow the current LWP or thread.

$pc	Current program counter accress in hexadecimal
$ins	Disassembly of the current instruction
$lineno	Current line number in decimal
$vlineno	Current `visiting' line number in decimal
$line	Contents of the current line
$func	Name of the current function
$vfunc	Name of the current `visiting' function
$class	Name of the class to which $func belongs
$vclass	Name of the class to which $vfunc belongs
$file	Name of the current file
$vfile	Name of the current file being visited
$loadobj	Name of the loadable object being visited
$vloadob	...
$scope	The scope of the current PC in back-quote notation
$vscope	...
$funcaddr	Address of $func in hexadecimal
$caller	Name of the function calling $func
$newhandlerid	Event ID of the handler most recently created
$firedhandlers	List of handler ids that caused the most recent stoppage. The handlers on this list are marked with a `*' in the output of the status command.
$proc	The process ID of the current process being debugged
$lwp	LWP ID of the current LWP (multithreaded programs only)
$thread	Thread ID of the current thread (multithread programs only)
$prog	Full path name of the loaded program
$oprog	Previous value of $prog. Very useful after follow-exec, when $prog reverts to "-".
$dllist	List of all load objects last opened with dlopen () or closed with dlclose ().
$exception	Pointer to the current C++ exception, or 0 if none
$exitcode	Exit status from the last run of the program. This value is an empty string if the process hasn't actually exited.
$machtype	If a program is loaded, $machtype returns its machine type: sparcv8 sparcv8+ sparcv9 intel. Otherwise it returns 'unknown'
$datamodel	If a program is loaded, $datamodel returns its data model: ilp32 lp64. Otherwise it returns `unknown.' To find the model of the program you've just loaded, use the following in your .dbxrc file: when prog_new -perm { echo machine: $machtype $datamodel; }

The following are valid only within the body of a when Command:

$handlerid

During the execution of the body $handlerid is the ID of the when command to which the body belongs.

$booting

Is set to `true' if the event occurs during the "boot" process. Whenever a new program is debugged, it is first booted so that the list and location of shared libraries can be ascertained. The process is then killed. While booting happens "behind the users back", contributing to the "Reading symbolic information for libc.so.1" messages, all events are still available. Use this variable to distinguish, for example, the sync and the syncrtld events occuring during execution started with a debug command and the ones occurring during exeuction started with a run Command.

The following are only valid within the body of a when Command and are event specific.

For event signals:

$sig	Signal number that caused the event
$sigstr	Name of $sig
$sigcode	Subcode of $sig if applicable
$sigcodestr	Name of $sigcode
$sigsender	Pid of sender of the signal if relevant, 0 otherwise

For event exit:

$exitcode

Argument passed to exit(). This value is also valid outside the body of a when Command. See above.

For event access:

$watchaddr	The address being written to, read from or executed.
$watchmode	One of "rwx" for read, write or execute followed by one of "ab" for after or before.

For events sysin and sysout:

syscode	$system call code
$sysname	system call name as defined in <sys/syscall.h>

For events dlopen and dlclose (only if a param was provided):

$dlobj

loadobject that cause the event

For event proc_gone:

$reason

Reason the process went away. Can be signal, exit Command, kill Command, or detach Command