dxdb(1X)dxdb(1X)Namedxdb - DECwindows debugger
Syntaxdxdb [options] file [coredump]
Description
The dxdb debugger is a DECwindows utility that lets you debug a C pro‐
gram, view its source code, and fix bugs found in the code. It uses
many of the same methods as the dbx(1) debugger.
Options-bd color Specifies the color of the window's border (color
displays only). The default is specified by means
of the Session Manager's Customize Window dialog
box.
-bg color Specifies the color of the window's background
(color displays only). The default is specified by
means of the Session Manager's Customize Window
dialog box.
-d dispname Specifies the display screen on which dxdb displays
its window. If the display option is not speci‐
fied, dxdb uses the display screen specified by
your DISPLAY environment variable. The display
option has the format hostname:number. Using two
colons (::) instead of one (:) indicates that DEC‐
net is to be used for transport. The default is
:0. For more information, see
-display dispname This option is the same as the -d option.
-fg color Specifies the color of the text (color displays
only). The default is black.
-fn font Specifies the font for all windows except the index
list box. The default font is menu12.
-geometry Specifies the width, length, and location of the
dxdb window. If the geometry option is not speci‐
fied, dxdb uses default values. The geometry
option has the format [widthxlength][{+-}x{+-}y].
For more information about the screen coordinate
system, see
file A C object file compiled with the -g option of the
cc(1) command. The -g option produces the appropri‐
ate symbol information in the object file.
coredump A core file that you can access through dxdb to
examine the state of a program that crashed.
-I dir Adds dir to the list of directories that dxdb
searches when looking for source files. Normally,
dxdb searches only in the current directory.
-t Specifies the title to be listed in the main win‐
dow's title bar.
Menus
When you invoke the debugger, dxdb displays the Control window. The
menu bar of the Control window contains the following menus:
· File
· Control
· Options
· Windows
· Functions
· Help
File Menu
The File menu lets you perform global actions affecting the entire
debugging session. It contains the following items:
Open... Reads in a new source file.
Make/Restart Builds a new executable and restarts the debugger.
Edit Edits a source file.
Quit Terminates the dxdb session.
Control Menu
The Control menu controls program execution. It contains the following
items:
Run Runs the program.
Step Runs the program in single- or multiple-line increments.
You set the step count using the Step window (see
Options Menu).
Skip Runs the program in single- or multiple-line increments
but views all code of a subroutine as a single step. You
set the skip count using the Skip window (see Options
Menu).
Continue Restarts a program after a Stop command, a breakpoint,
or a Skip or Step function.
Stop Stops execution of the program.
Return Continues execution until the current procedure returns.
Options Menu
The Options menu items create the following windows:
Run... Lets you supply arguments to a program. The Run window
consists of an input area and the following control
buttons:
· Run with Argument
· Run
· Close
To supply an argument to a program, enter it in the
input area and click on the Run with Arguments button.
To run a program without specifying an argument, click
on the Run button. Clicking on the Close button quits
the window.
Step... Specifies the line increment (step count) in which dxdb
runs a program. The Step window consists of an input
area, plus (+) and minus (-) accelerator buttons, and
the following command buttons:
· Step Count
· Step Once
· Close
To set a step count, either click on the appropriate
accelerator button until you reach the desired count or
enter the count in the input area. Click on the Step
Count button, and then return to the Control window and
click on the Step button. The debugger executes the
specified number of lines of code each time you click on
the Step button.
To return to single-step increments, use the Step Once
button.
Skip... Sets the number of lines (skip count) that dxdb skips
when running a program. The Skip window consists of an
input area, plus (+) and minus (-) accelerator buttons,
and the following command buttons:
· Skip Count
· Skip Once
· Close
You set the skip count as you set the step count. How‐
ever, if dxdb encounters a subroutine call when execut‐
ing a skip, it executes the entire routine as a single
skip and resumes the skip count when it returns from the
call.
Windows Menu
The Windows menu items create the following windows:
Assign... Assigns a value to a specified variable. The Assign win‐
dow consists of the following input areas:
· Variable prompt
· Value prompt
· Assign button
· Close button
To assign a value to a variable, enter a variable in the
Variable text field, enter a value in the Value text
field, and click on the Assign button.
Breakpoints... Displays the current breakpoints and tracepoints. To
delete a breakpoint or tracepoint, select it in the text
and click on the Delete button.
Dump... Displays the values of all currently active local vari‐
ables. The debugger updates the contents of this window
each time you stop execution of the program (using the
Step, Skip, or Stop function, or by setting a break‐
point).
Examine... Displays the values of specified variables. This window
consists of the following areas:
· Text area
· Examine prompt
· Add button
· Delete button
· Close button
To examine a variable, enter its name in the Examine
text field and click on the Add button. The debugger
displays the variable's current value in the window's
text area.
To delete a variable from the Examine window, click on
its name in the window's text area and then click on the
Delete button.
Stack Lets you view elements of the program execution stack.
The program that dxdb is running places an entry on this
stack each time program control executes one of its rou‐
tines. Each element on the stack contains the routine
name and the parameters passed to that routine. The
debugger updates this window each time you stop the exe‐
cution of the program.
Make... Displays the output of the Make/Restart command. The
Restart Command field is executed when the Make/Restart
command is executed and can be edited to suit the pro‐
gram being debugged.
Functions Menu
The Functions menu contains the following items:
Whatis Returns the data type of a variable. Select a variable
currently displayed in the Source window and then choose
Whatis from the Functions menu. Whatis returns the vari‐
able's data type in the following format:
variable - routine.datatype variable;
Whereis Returns a list of routines from which you can locate a
variable. Select a variable from the Source window and
then choose Whereis from the Functions menu. Whereis
returns the variable's location in the following format:
routine.variable routine.variable ...
Which Returns the scope of the variable (local or global) that
is currently active. Select a variable from the Source
window and then choose Which from the Functions menu.
Which returns the variable's scope in the following for‐
mat:
variable - rotuine.function...variable
Help Menu
The Help menu displays information about dxdb.
In addition to those pulldown menus, there are several pop-up menus:
Control Pop-up Menu
The Control pop-up menu duplicates the Control pull-down menu; it con‐
trols program execution. To invoke this menu, press MB2 on the Source
Area.
Examine Pop-up Menu
The Examine pop-up menu lets you examine the value of variables, and
set and delete breakpoints and tracepoints. To invoke this menu, press
the Shift key and click MB2 in the Source Area. The menu items operate
on text in the Source area. If you position the pointer over some text
before invoking the menu, the menu options refer to that text. If
there is no text under the pointer, dxdb uses text that is highlighted.
The menu items are as follows:
Print Prints the value of a variable in the text area.
Print * Prints the value of a variable treated as a pointer.
Examine Enters a variable in the Examine window.
Examine * Enters a variable in the Examine window treated as a
pointer.
Delete Examine Removes a variable from the Examine window.
Stop in Func Sets a breakpoint in the selected function.
Trace in Func Sets a tracepoint in the selected function.
The Examine and Print options have submenus that let you view the val‐
ues in hexadecimal notation.
Breakpoints Pop-up Menu
This menu lets you set and delete breakpoints. To invoke the menu,
press MB2 in the Margin Area. All options operate on the text indicated
by the pointer when you invoke the menu. The menu options are as fol‐
lows:
Set at Line Sets a breakpoint at the specified line.
Set in Func Sets a breakpoint in the specified function.
Global Sets a global breakpoint.
Random Func Sets a breakpoint in any function in the program.
Random Line Sets a breakpoint at any line in the program.
Delete BP Deletes a breakpoint whose symbol is under the cursor.
The Set at Line and Set in Func options have submenus that let you set
conditional breakpoints.
Tracepoints Pop-up Menu
This menu lets you set and delete tracepoints. To invoke the menu,
press Shift/MB2 on the Margin Area. All options operate on the text
indicated by the pointer when you invoke the menu. The Tracepoint
pop-up menu has the following items:
Trace Global Sets a global tracepoint.
Trace at Line Sets a tracepoint at the specified line.
Trace in Func Sets a tracepoint in the specified function.
Delete Trace Deletes a tracepoint whose symbol is under the cursor.
X Defaults
The dxdb debugger uses the values in the .Xdefaults file when you
logged in and uses the appropriate resource specification to customize
the appearance or characteristics of its windows. The format for a
resource specification in the .Xdefaults file is as follows:
[name*]resource: value
name Specifies the application name or, in the case of tool‐
kit-based applications, the name string that restricts
the resource assignment to that application or to a com‐
ponent of an application. If this argument is not speci‐
fied, the resource assignment is globally available to
all X applications.
resource Specifies the X resource.
value Specifies the value that is to be assigned to the
resource.
Because each X-based application can consist of a combination of wid‐
gets (for example, push buttons and a scroll bar), you can form the
name string by adding widget class and name identifiers to the string.
For additional information about adding class and name identifiers, see
Files
/usr/lib/X11/app-defaults/Db
~/.Xdefaults
core
See Alsodbx(1), dxterm(1X), X(1X)
Guide to the dxdb Debugger
dxdb(1X)
