xxgdb(1)
NAME
xxgdb - X window system interface to the gdb debugger.
SYNOPSIS
xxgdb [ -toolkitoption ... ] [-xxgdboption ... ] [-gdboption ... ] [objfile [ corefile ]]
DESCRIPTION
Xxgdb is a graphical user interface to the gdb debugger under the X Window System. It provides visual feedback and mouse input for the user to control program execution through breakpoints, to examine and traverse the function call stack, to display values of variables and data structures, and to browse source files and functions. Xxgdb allows initial gdb commands stored in the file .gdbinit to be executed immediately after the symbolic information is read. If .gdbinit does not exist in the current directory, the user's home directory is searched ( /.gdbinit). Option -nx can be used to prevent xxgdb from executing this file. Option -i can be used to change the file name of command file. Objfile is an object file produced by a compiler with the appropriate option (-g) specified to produce symbol table information for gdb. If a file named core exists in the current directory or a corefile is specified, xxgdb can be used to examine the state of the program when the core dump occurred. The name of the debugger invoked by xxgdb is, by default, gdb, but it can be overridden with the environment variable XXGDB_DEBUGGER or with the db_name option.
OPTIONS
Xxgdb accepts all of the standard X Toolkit command line options (see X(1)), and all the gdb options (see gdb(1)), plus the following xxgdb specific options: -db_name debuggername Specify the name of the debugger to override the default "gdb". WARNING : by default prompt is the name of the debugger enclosed in parenthesis followed by a space. So if the prompt is still "(gdb) ", you HAVE TO use -db_prompt "gdb" -db_prompt promptstring Specify to xxgdb what is the debugger prompt. The default is to expect the prompt to be the name of the debugger enclosed in parenthesis followed by a space (eg, "(gdb) "). -i filename Specify the filename of initial gdb command file. The default is ".gdbinit". -nx Do not execute .gdbinit file (or file specified with -i) -bigicon Uses a 64x64 icon instead of the default 48x48 icon.
SUBWINDOWS
Xxgdb consists of the following subwindows:
File Window Display the full pathname of the file displayed in
the source window, and the line number of the
caret.
Source Window Display the contents of a source file.
Message Window Display the execution status and error messages of
xxgdb .
Command Window Provide a list of the common gdb commands which are
invoked by simply clicking the LEFT mouse button.
Dialogue Window Provide a typing interface to gdb.
Display Window Provide a window for displaying variables each time
execution stops.
Popup Windows Provide windows for displaying variables (see
"Displaying C Data Structures" below).
The relative sizes of the source window, command window, and the
dialogue window can be adjusted by dragging the grip (a small square
near the right edge of a horizontal border) with the LEFT mouse button
down.
SELECTION
Text selection in the source window is modified to make it easier to select C expressions. LEFT mouse button down selects a C expression by highlighting it in reverse-video. LEFT mouse button down also positions the caret and updates the line label accordingly. C expression selection is based on the resource delimiters which determines the set of characters that delimits a C expression. (The default word selection behavior in the Athena text widget selects a word delimited by white spaces.) Text selection adjustment is possible by holding the LEFT mouse button down and dragging. A LEFT mouse button click with the SHIFT button down prints the value of the expression selected.
SCROLLBAR
Pressing the LEFT mouse button scrolls the text forward, whereas pressing the RIGHT mouse button scrolls the text backward. The amount of scrolling depends on the distance of the pointer button away from the top of the scrollbar. If the button is pressed at the top of the scrollbar, only one line of text is scrolled. If the button is pressed at the bottom of the scrollbar, one screenful of text is scrolled. Pressing the MIDDLE mouse button changes the thumb position of the scrollbar. Dragging the MIDDLE mouse button down moves the thumb along and changes the text displayed.
IOWIN and NOIOWIN COMMAND
If compiled, with the right option, xxgdb can use a separate io window to talk to gdb, so program output is not confused with gdb output. Type command 'iowin' in Dialogue Window to create io window. If you get 'Undefined command' error message, then xxgdb was not compiled for that feature. The program xxgdbiowin is used for this io window. If xxgdb was compiled with iowin support, typing 'noiowin' will close the io window and reset the controlling terminal of the debugger.
COMMAND BUTTONS
Execution Commands
run Begin program execution.
cont Continue execution from where it stopped.
next Execute one source line, without stepping into any function
call.
step Execute one source line, stepping into a function if the
source line contains a function call.
finish Continue execution until the selected procedure returns;
the current procedure is used if none is selected.
Breakpoint Commands
break Stop program execution at the line or in the function
selected. To set a breakpoint in the program, place the
caret at the start of the source line or on the function name
and click the break button. A stop sign will appear next to
the source line.
tbreak Set a breakpoint enabled only for one stop. This is the same
as the break button except the breakpoint is automatically
disabled the first time it hit.
delete Remove the breakpoint on the source line selected or the
breakpoint number selected.
show brkpts
Show the current breakpoints (both active and inactive).
Stack Commands
stack Show a stack trace of the functions called.
up Move up one level on the call stack.
down Move down one level on the call stack.
Data Display Commands
print Print the value of a selected expression. (also see
"Displaying C Data Structures" below)
print * Print the value of the object the selected expression is
pointing to. (also see "Displaying C Data Structures" below)
display Display the value of a selected expression in the display
window, updating its value every time execution stops.
undisplay Stop displaying the value of the selected expression in the
display window. If the selected expression is a constant, it
refers to the display number associated with an expression in
the display window.
args Print the arguments of the selected frame.
show display
Show the names of currently displayed expressions.
locals Print the local variables of the selected frame.
stack Print a backtrace of the entire stack.
Miscellaneous Commands
search Pop up a search panel which allows both forward (>>) and reverse
(<<) search of text strings in the source file. Hitting
carriage return after entering the search string will begin a
forward search and pop down the search panel.
file Pop up a directory browser that allows the user to move up and
down in the directory tree, to select a text file to be
displayed, to select an executable file to debug, or to select a
core file to debug. Directory entries are marked with a
trailing slash (`/') and executables with a trailing asterisk
(`*'). Filenames beginning with a dot (`.') or ending with a
tilde (`~') are not listed in the menu.
search Pop up a search panel which allows both forward (>>) and reverse
(<<) search of text strings in the source file. Hitting
carriage return after entering the search string will begin a
forward search and pop down the search panel.
yes Send 'y' (yes) to gdb. To be used when gdb requires a yes/no
response.
no Send 'n' (no) to gdb. To be used when gdb requires a yes/no
response.
quit Exit xxgdb.
I/O Win
Create io window.
No I/O Win
Delete io window.
Displaying C Data Structures
Xxgdb provides some primitive support for graphically displaying C
structures and the ability of following pointers. Pressing the RIGHT
mouse button on the print (or print *) command button displays the
value of the selected expression (or the value the selected expression
is pointing to) in a popup. If the value is a pointer or a structure
containing pointers, the user can examine the value of the object that
pointer is pointing to by clicking the pointer value. This will create
another popup that displays the object the pointer points to. Clicking
the label of the popup pops down itself and all of its descendants.
X DEFAULTS
To change the default values of widget resources used in xxgdb, you
need to reference the widgets by name or by class. The widget
hierarchies for the main window, the file menu, the search dialog box,
and the popup data display used in xxgdb are shown as follows, with the
name of the widget followed by the name of its class in parentheses:
Main window:
toplevel (ToplevelShell)
vpane (Paned)
fileWindow (Form)
fileLabel (Label)
lineLabel (Label)
sourceForm (Form)
sourceWindow (AsciiText)
messageWindow (Label)
commandWindow (Box)
run (Command)
cont (Command)
next (Command)
step (Command)
finish (Command)
break (Command)
tbreak (Command)
delete (Command)
up (Command)
down (Command)
print (Command)
print * (Command)
display (Command)
undisplay (Command)
args (Command)
locals (Command)
stack (Command)
search (Command)
file (Command)
show display (Command)
show brkpts (Command)
yes (Command)
no (Command)
quit (Command)
dialogWindow (AsciiText)
displayWindow (AsciiText)
File menu:
File Directory (TransientShell)
popup (Paned)
fileMenuLabel (Label)
fileMenu (List)
cancelButton (Command)
Search dialog box:
Search (TransientShell)
searchPopup (Dialog)
<< (Command)
>> (Command)
DONE (Command)
Data display popup:
Data Popup (TransientShell)
popup (Form)
label (Label)
dataDpyWindow (AsciiText)
In addition to the standard X resources, xxgdb uses the following
application-specific resources for user customization. The value in
parentheses is the default value.
bell If True, the bell is on. (True)
displayWindow
If True, the display window appears on start up. (False)
delimiters
The set of delimiters for word selection. ("
!%^&*()+=~|;:{},/#<?\"\n\t")
stop_color
Color of the stop sign. (Red)
arrow_color
Color of the arrow sign. (Blue)
updown_color
Color of the updown sign. (Blue)
bomb_color
Color of the bomb sign. (Red)
dataDpyMaxHeight
Maximum height of the data display window. (300)
dataDpyMaxWidth
Maximum width of the data display window. (600)
prompt The prompt string used in xxgdb. ("(xxgdb) ")
db_name
The name of the debugger program. ("gdb")
db_prompt
The prompt string of the debugger program. ("(gdb) ")
gdbinit
The filename of initial command file. (".gdbinit")
nx If True, xxgdb will not execute .gdbinit at start-up. (False)
tabstop
When displaying source code, the width (in spaces) of a tab. (8)
FILES
a.out default object file core default core file ~/XDbx resources file (or /usr/lib/X11/app-defaults/XDbx) .gdbinit local initial commands file ~/.gdbinit user's initial commands file
SEE ALSO
X(1), gdb(1)
COPYRIGHT
Copyright 1989 The University of Texas at Austin. Copyright 1990 Microelectronics and Computer Technology Corporation. Copyright 1990-1994 Thomson Consumer Electronics, Inc.
AUTHOR
Po Cheung. Pierre Willard.
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
