Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
DDB(8)			FreeBSD	System Manager's Manual			DDB(8)

NAME
     ddb -- configure DDB kernel debugger properties

SYNOPSIS
     ddb capture [-M -core] [-N	-system] print
     ddb capture [-M -core] [-N	-system] status
     ddb script	scriptname
     ddb script	scriptname=script
     ddb scripts
     ddb unscript scriptname
     ddb pathname

DESCRIPTION
     The ddb utility configures	certain	aspects	of the ddb(4) kernel debugger
     from user space that are not configured at	compile-time or	easily via
     sysctl(8) MIB entries.

     To	ease configuration, commands can be put	in a file which	is processed
     using ddb as shown	in the last synopsis line.  An absolute	pathname must
     be	used.  The file	will be	read line by line and applied as arguments to
     the ddb utility.  Whitespace at the beginning of lines will be ignored as
     will lines	where the first	non-whitespace character is `#'.

OUTPUT CAPTURE
     The ddb utility can be used to extract the	contents of the	ddb(4) output
     capture buffer of the current live	kernel,	or from	the crash dump of a
     kernel on disk.  The following debugger commands are available from the
     command line:

     capture [-M core] [-N system] print
	     Print the current contents	of the ddb(4) output capture buffer.

     capture [-M core] [-N system] status
	     Print the current status of the ddb(4) output capture buffer.

SCRIPTING
     The ddb utility can be used to configure aspects of ddb(4)	scripting from
     user space; scripting support is described	in more	detail in ddb(4).
     Each of the debugger commands is available	from the command line:

     script scriptname
	     Print the script named scriptname.

     script scriptname=script
	     Define a script named scriptname.	As many	scripts	contain	char-
	     acters interpreted	in special ways	by the shell, it is advisable
	     to	enclose	script in quotes.

     scripts
	     List currently defined scripts.

     unscript scriptname
	     Delete the	script named scriptname.

EXIT STATUS
     The ddb utility exits 0 on	success, and >0	if an error occurs.

EXAMPLES
     The following example defines a script that will execute when the kernel
     debugger is entered as a result of	a break	signal:

	   ddb script kdb.enter.break="show pcpu; bt"

     The following example will	delete the script:

	   ddb unscript	kdb.enter.break

     For further examples, see the ddb(4) and textdump(4) manual pages.

SEE ALSO
     ddb(4), textdump(4), sysctl(8)

HISTORY
     The ddb utility first appeared in FreeBSD 7.1.

AUTHORS
     Robert N M	Watson

BUGS
     Ideally, ddb would	not exist, as all pertinent aspects of ddb(4) could be
     configured	directly via sysctl(8).

FreeBSD	9.2		       December	24, 2008		   FreeBSD 9.2

NAME | SYNOPSIS | DESCRIPTION | OUTPUT CAPTURE | SCRIPTING | EXIT STATUS | EXAMPLES | SEE ALSO | HISTORY | AUTHORS | BUGS

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=ddb&sektion=8&manpath=FreeBSD+9.2-RELEASE>

home | help