Debugger Command Syntax¶
Command names and arguments are separated with spaces like POSIX shell syntax. Parenthesis around the arguments and commas between them are not used. If the first non-blank character of a line starts with #, the command is ignored.
Commands are split at whereever ;; appears. This process disregards any quotes or other symbols that have meaning in Python. The strings after the leading command string are put back on a command queue, and there should be white space around ‘;;’.
Within a single command, tokens are then white-space split. Again, this process disregards quotes or symbols that have meaning in Python. Some commands like eval, macro, and break have access to the untokenized string entered and make use of that rather than the tokenized list.
Resolving a command name involves possibly 4 steps. Some steps may be omitted depending on early success or some debugger settings:
1. The leading token is first looked up in the macro table. If it is in the table, the expansion is replaces the current command and possibly other commands pushed onto a command queue. Run help macros for help on how to define macros, and info macro for current macro definitions.
2. The leading token is next looked up in the debugger alias table and the name may be substituted there. See “help alias” for how to define aliases, and “show alias” for the current list of aliases.
3. After the above, The leading token is looked up a table of debugger commands. If an exact match is found, the command name and arguments are dispatched to that command.
4. If after all of the above, we still don’t find a command, the line may be evaluated as a Python statement in the current context of the program at the point it is stoppped. However this is done only if “auto evaluation” is on. It is on by default.
If auto eval is not set on, or if running the Python statement produces an error, we display an error message that the entered string is “undefined”.
If you want python-, ipython- or bpython-like shell command-processing, it’s possible to go into an python shell with the corresponding command. It is also possible to arrange going into an python shell every time you enter the debugger.