void beh_debug (pnt, type) void *pnt; char *type;
- pointer of the structure to be displayed
name of the structure to be displayed. type can be any of "befig",
"beout", "bereg", "bemsg", "bepor", "begen", "berin", "bebus", "beaux",
"bebux", "biabl", "binode", "beder", "bequad", "abl", "integer", "long",
"short", "character", "ptype", "chain"
When called, beh_debug() displaies the structure pointed by pnt then, prints the line:
- COMMAND >>
and waits for a command being entered by the user. If pnt is a NULL pointer or type doesn't represent a known structure, beh_debug() exits without making any action.
To display the structure, beh_debug() prints a line per field. Fields containing immediate value (integer, character, string, ...) are displayed in the following form:
- name_of_the_field : value_of_the_field
Fields containing a pointer are marked by the symbol ->. If the field contains a NULL pointer, the field is displayed as:
- -> name_of_the_field :
In the other case, beh_debug() prints :
- -> name_of_the_field : available
Two kinds of command are accepted by the displayer.
A command can be the name of a field containing a pointer. The command is accepted only if the pointer is not a NULL pointer (field displayed as "available"). When the debugger receives such a command, it first pushes the current structure on its stack then, displaies the structure pointed by the named field.
The second kind of commands are predefined commands :
- to exit from the debugger
- to return to the previous structure
- to put a stop mark on the current structure
- to return to the first structure (pointed by pnt)
- to return to the last structure marked with a stop mark
- to save the current structure in a static table. At most 10 structures may be saved. (example : "_save 1" saves the current structure in the entry number ! of the table)
- to jump to a saved structure (example : "_jump 1" dislpaies the etructure save in the entry number 1 of the table).
- displaies a field under a given format. (example : "_display next integer" displaies the field named next as an integer).
In addition to these commands, the command . (dot) can be used to repete the last command.
#include <beh109.h> struct beout *beout_pnt; beh_debug (beout_pnt , "beout");
beh_debug() uses an internal stack. The message "stack overflow" is printed if too many structures have been pushed on the stack.