After starting the debugger as explained in the topic Starting the
Debugger, bring a program under debugger control using one of the
following two techniques:
- Run a specified image. This is the most common technique and is
described below.
- Run an image by specifying a symbol for a foreign command or a DCL
command. This technique is described in the topic Running an Image
by Specifying a Symbol.
To run a specified image:
1. Choose Run Image... from the File menu on the main window. The
Run Image... dialog box appears, which lists:
- A Directories list that contains the parent directory and any
subdirectories contained in the current directory
- A Filter field; by default this specifies the .EXE files in
your current directory
- An Images list that contains the names of images in the current
directory that meet the filter specification
- An Arguments field to pass any required arguments to the image
to be run
- A Heap Analyzer button to run the Heap Analyzer
- An Image field to display and specify the full file
specification of the image to be run
- An OK button to run the image specified in the Image field and
dismiss the dialog box
- A Filter button to display a list of files that meet the
specification in the Filter field
- A Cancel button to dismiss the dialog box without taking and
further action
- A Help button to display this help information
2. In the Directories list, click on the name of the appropriate
subdirectory and click on Filter to list the (filtered) files in
the subdirectory. The debugger also displays, in the Directories
list, the parent directory and any subdirectories of the selected
directory.
3. In the Images list, click on the name of the image to be debugged.
The Image field now shows the image specification. You can edit
this specification as needed.
4. If applicable, enter arguments to be passed to the program in the
Arguments field. Quoted strings, may require additional quotation
marks because the debugger strips quotes when parsing the string.
5. To run the Heap Analyzer, click the Heap Analyzer button.
6. Click on OK to dismiss the dialog box and run the spcified image.
When the program is under debugger control, the debugger:
- Displays the program's source code in the main window.
- Suspends execution at the start of the main program. The
current-location pointer, to the left of the source code, shows the
line whose code will be executed next.
The message displayed in the command view indicates the name of the
main program unit and also indicates that the debugging session is
initialized for the source language of the program. The initialization
sets up language-dependent debugger parameters. These parameters
control the way the debugger parses names and expressions, formats
debugger output, and so on.
You can now debug your program.
With certain programs, the debugger suspends execution at the start of
some initialization code, before the main program, and displays the
following message:
Type GO to reach main program
With some of these programs (for example, Ada programs), the first
breakpoint lets you debug the initialization code using full symbolic
information.
Note the following restrictions about running a program under debugger
control:
- You cannot use the procedure just described to connect the debugger
to a running program.
- You cannot run a program under debugger control over a DECnet link.
Both the image to be debugged and the debugger must reside on the
same node.