Gdb vs. dbx feature comparison

gdb	dbx
Invocation
gdb program gdb program core gdb program pid	dbx progam dbx program core dbx program pid
gdb -c core gdb -p pid Note: need to specify program explicitly	dbx - core dbx - pid (program is found automatically) Note: dbx cannot debug core files and live processes without access to program file, i.e. a.out
gdb -s file (read symbols from file)	-
gdb -x file	dbx ... < file dbx -s file ...
-tty device (Run using device for your program’s standard input and output)	dbxenv run_io pty dbxenv run_pty device
-write (open executable and core file for writing)	-
Exiting
quit Ctrl-d	exit
Executing shell commands
shell command	ksh command /bin/sh command Note: you can use any ksh command, including function definition. See “help ksh differences” for limitations.
Logging
set logging show logging	dbxenv session_log_file_name file dbxenv session_log_file_name
-	dbxenv output_log_file_name file dbxenv output_log_file_name (logs only commands, not their output)
set logging redirect [on|off]	- Note: equivalent to off
set logging overwrite [on|off]	- Note: equivalent to on
Commands (general)
Abbreviation - automatic (can use 's' instead of 'step')	Need to use ksh 'alias' command to define aliases
Auto-completion with Tab	No auto-completion
Command repeat with Ret	Command repeat with '!' and UpArrow Ret
Built-in help
help [command]	help [command]
apropos keyword	help -k keyword
Debugging information support
stabs (GNU), dwarf2, -g -O	stabs (SUN), dwarf2, -g -O
Macro support (-g3)	Macro support (-g3); Sun Studio compilers don't generate debug info for macros, though.
(status unknown)	.ldynsym support (symbols in stripped loadobject)
Starting a program
run [arguments][ < input_file] [ > output_file	run [arguments][ < input_file] [ > output_file]
start (run and stop in “main”)	- Note: only available in GUI mode when used from Sun Studio IDE
Program environment
set args args	runargs args
show args	debug
path dir	PATH=dir:$PATH
show paths	echo $PATH
set environment varname [=value ]	varname=value
unset environment varname	unset varname
cd directory	cd directory
pwd	pwd
-	any other ksh command (with certain limitations; see “help ksh differences”)
Attaching
attach pid	attach pid debug program pid debug - pid
detach	detach
-	detach -stop
Killing the child process
kill	kill (builtin) /usr/bin/kill
Debugging Multithreaded Applications
info threads	threads
thread threadno	thread threadid
-	thread -info [threadid]
-	thread -blocks [threadid] thread -blockedby [threadid]
-	syncs (list all synchronization objects). Note: available on Solaris only.
-	sync -info addr (show information about the synchronization object). Note: available on Solaris only.
thread apply [threadno] [all] command	-
-	lwps
-	lwp lwpid
-	lwp [lwpid] -info (displays the name, home, and masked signals)
-	lwp [lwpid] -setfp addr lwp [lwpid] -resetfp (temporarily set frame pointer to specified value)
-	OpenMP support.
Debugging Programs with Multiple Processes
set follow-fork-mode parent	dbxenv follow_fork_mode parent
set follow-fork-mode child	dbxenv follow_fork_mode child
-	dbxenv follow_fork_mode ask
set detach-on-fork on/off	- Note: always detaches; it is possible to debug both processes, but only using Sun Studio IDE
info forks fork fork-id detach fork fork-id delete fork fork-id	-
Process snapshots
checkpoint info checkpoints restart checkpoint-id delete checkpoint checkpoint-id	- Note: dbx has different mechanism for that; see “help save/restore/replace” commands for more information.
Breakpoints
break function	stop in function
break +offset break -offset	stop at $[$lineno+offset] stop at $[$lineno – offset] Note: you can define helper function in .dbxrc that will save you from typing all that stuff.
break [filename:]linenum	stop at [filename:]linenum
break filename:function	-
break *address	stopi at address stop at address -instr
break (stop on next instruction in current stack frame)	- Note: Can use “stopi at $npc”, but on sparc only
break ... if cond condition bnum expression	stop ... -if cond
condition bnum (removes condition)	-
tbreak args	stop ... -temp
-	stop inmethod func stop inmember func stop infunction func stop inclass classname [ -recurse | -norecurse ] inobject object_address [ -recurse | -norecurse ]
step; cont next; cont	stop step stop next
catch signal [signame ]	stop sig signal [code]
-	stop fault
catch throw [ exceptname] Note: not very useful since stop after exception is thrown; doesn't work in code called from gdb	intercept [-all] [-x] [-set] [typename] stop throw [-unhandled] [-unexpected] [typename]
catch catch [exceptname]	- Note: use “whocatches” command
catch stop	stop stop
-	stop attach stop detach
-	stop sync
-	stop syncrtld
-	stop lastrites (Solaris only)
catch load [ lib-path ] catch unload [ lib-path ] Note: unavailable on Linux and Solaris	stop dlopen [ lib-path ] stop dlclose [ lib-path ]
-	stop exit [ exitcode ]
catch fork catch vfork catch exec Note: no other system calls are supported	stop sysin [sysin code|name] stop sysout [sysin code|name]
finish Note: can't specify function to catch return from	stop returns [func] Note: has bug(s), still unresolved.
-	stop lwp_exit (Solaris only)
catch exit catch start Note: not implemented on Linux and Solaris	stop proc_gone stop prog_new
tcatch ...	stop ... -temp
-	stop timer seconds
watch variable Note: need to re-enable manually	stop change variable
watch expr Note: need to re-enable manually	stop if expr stop cond expr
mem addr-expr addr-expr mode	stop access mode addr-expr [ , byte-size-expr
rwatch awatch Note: need to re-enable manually, doen't work on Solaris and Linux.	-
catch thread_start catch thread_exit	stop thr_exit [-thread tid] stop thr_create [ tid ]
catch thread_join	-
-	stop ... -resumeone (when evaluating stop condition, resume only one thread).
-	stop ... -in func
ignore bnum count	stop ... -count count handler -count count bnum
break linespec thread threadno	stop ... -thread tid
-	stop ... -lwp lwpid
hbreak args thbreak args	-
rbreak regex	- Note: need to use funcs command and manually set breakpoints with “stop in”
info breakpoints [n] info watchpoints [n]	status [n]
clear clear linenum clear filename:linenum	clear clear linenum clear filename:linenum
clear function clear filename:function	-
delete [breakpoints] [range ...]	delete [breakpoints] delete all
Pending breakpoints	- Note: you can load shared library with “loadobject -load lib” and set breakpoints after that or run your program once without any breakpoints so that dbx become aware of all libraries.
set breakpoint auto-hw on/off	-
disable [breakpoints] [range ...]	handler -disable [breakpoints]
enable [breakpoints] [range ...]	handler -enable [breakpoints]
enable [breakpoints] once range ... enable [breakpoints] delete range ...	-
commands [bnum ] ... command-list ... end	when ... { cmd; } wheni ... { cmd; }
-	trace next trace at lineno trace in func trace modify addr-expr [ , byte-size-expr ] trace ...
Continuing and Stepping
continue [ignore-count ] fg [ignore-count ]	cont
step [count]	step [count] [tid | lwpid]
next [count]	next [count] [tid | lwpid]
set step-mode on stepi [count]	stepi [count] [tid | lwpid]
nexti [count]	nexti [count] [tid | lwpid]
-	step to [func]
-	step ... -sig signal
until [location] (Execute until the program reaches a source line greater than the current or specified location).	-
advance location	cont at line
Signals
info signals info handle	catch, ignore
handle signal stop	catch signal
handle signal nostop	ignore signal
handle signal print	when sig signal { print $signal; print $sigstr; } trace sig signal
handle signal noprint	- Note: no information is printed about ignored signals
handle signal pass handle signal noignore	ignore signal
handle signal nopass handle signal ignore	- Note: use cont with no -sig to cancel current signal after stopping because of it
Examining the Stack
backtrace [n] bt [n]	where [n]
backtrace [-n] bt [-n]	-
backtrace full [n]	-
set backtrace past-main on/off	-
set backtrace past-entry on/off	-
-	hide [ regular_expression ] unhide [ number | regular_expression ] unhide (hide stack frames in “where” command output)
set backtrace limit n set backtrace limit 0 (default is unlimited)	dbxenv stack_max_size n Note: default is 100; no “unlimited” option
show backtrace limit	dbxenv stack_max_size echo $DBX_stack_max_size
frame [args]	frame [n] Note: can't use address to identify stack frame
select-frame [args]	> /dev/null frame [n]
up [n] down [n]	up [n] down [n]
up-silently [n] down-silently [n]	> /dev/null up [n] > /dev/null down [n]
frame	where 1
info frame	-
info locals	dump
info catch	whocatches type
Examining Source Files
list linenum	list -w linenum
list function	list function
-	list -a function (lists entire function)
list	list
list -	list -10
set listsize count show listsize	dbxenv output_list_size count dbxenv output_list_size
list first,last	list first,last
list ,last	list last, - [n]
list first,	list first,+[n]
list +	list [+N]
list -	list - [N]
list *address	-
-	file [filename] (view or set current file)
edit edit number edit function edit filename:number edit filename:function edit *address	$EDITOR filename Note: need to find source file manually with 'whereis [-a]' command.
forward-search regexp search regexp	search [string]
reverse-search regexp	bsearch [string]
Specifying Source Directories
directory dirname ... dir dirname ... directory	use [dirname] Note: “use” is deprecated and replaced with pathmap.
set substitute-path from to	pathmap from to
unset substitute-path [path]	pathmap -d [path]
show substitute-path [path]	pathmap
Source and Machine Code
info line linespec	- Note: need to look at “list -i linespec” output
disassemble [addr]	dis [addr]
-	dis -a [addr] (disassemble entire function)
-	list -i [linespec] (intermix source lines and assembly code)
Examining Data
print /f expr	print -f expr
print /f	-
-	> FILE print ... (print to a file)
Artifcial arrays (p )	-
-	Array slicing (p array[2..5])
-	Pretty-printing (allows an application to provide it's own rendition of an expressions value through a function call, see “help prettyprint”).
x/nfu addr	x addr [/nf] examine addr [/nf] Note: unit size is governed by format, 'f'
display[/fmt] expr	display [-f fmt] expr
undisplay dnums ... delete display dnums ...	undisplay dnums ...
disable display dnums ... enable display dnums ...	-
display	display
-	watch (same as display, but expression is re-parsed at each stopping point)
set print address on/off	-
set print symbol-filename on/off	-
set print max-symbolic-offset max-offset	-
set print array on/off	- (equivalent to off)
set print array-indexes on/off	- (equivalent to off)
set print elements number-of-elements	-
set print repeats	-
set print null-stop	-
set print pretty on/off	- Note: equivalent to “on”
set print sevenbit-strings on/off	-
set print union on/off	-
set print demangle on/off set print asm-demangle on/off	- Note: usually both forms are displayed
set print object on/off	print -d ... Note: equivalent to “on”
set print static-members on/off	-
set print vtbl on/off	-
$ (previously printed expression)	-
show values (values history)	-
Convenience variables Example: set $foo = *object_ptr Note: these variables are typed.	Environment variables Example: foo=$[*object_ptr] Note: type of expression is not recorded in the variable.
show convenience	set
init-if-undefined $variable = expression	-
info registers	regs
info all-registers	regs -f | -F
info registers regname ...	print $regname
info float (floating point registers only)	-
info vector	-
info udot	-
info auxv	-
cache nocache (cache target memory)	-
Memory access checking
set mem inaccessible-by-default [on|off]	-
-	check -access
-	check -memuse
-	check -leaks
C Preprocessor Macros
macro expand expression macro exp expression	-
macro expand-once expression	-
info macro macro	-
macro define macro [(arglist)] replacement-list macro undef macro	-
macro list	-
Examining the Symbol Table
info address symbol	- Note: “print &symbol” should suffice.
info symbol addr	whereis -a addr Note: with 'check -memuse', shows allocation stack for heap-allocated memory region.
whatis arg	whatis [-e] arg
ptype arg	whatis [-e] arg
info types [regexp]	whatis -t [typename]
info scope location	-
info source	module -v file Note: dwarf info is not displayed correctly for object files.
info sources	modules -v files
info functions regexp	funcs regexp
info variables (All global and static variable names, or those matching REGEXP)	-
Altering execution
set var=value	assign var=value
assign $reg=value	assign $reg=value
jump linespec	cont at linespec
jump *address	assign $pc=address; cont
signal signal	cont -sig signal
return	pop
return expression	-
print expr call expr Note: abnormal termination affects debuggee	print expr call expr Note: abnormal termination doesn't affect debuggee; use “pop -c” to “cancel” call.
set unwindonsignal	- Note: equivalent to off
set write on/off (open executable or core for writing)	- Note: equivalent to off
-	fix
Debugging Information in Separate Files
set debug-file-directory directory	dbxenv debug_file_directory directory
show debug-file-directory	dbxenv debug_file_directory
Miscellaneous
set prompt newprompt	PS1=newprompt PS2=secondprompt

There's similar table in built-in dbx help. Use “help FAQ” and navigate to seciton A.1.