(octave.info)Debug Mode

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Enter node , (file) or (file)node

13.4 Debug Mode
===============

There are three additional support functions that allow the user to find
out where in the execution of a script Octave entered the debug mode,
and to print the code in the script surrounding the point where Octave
entered debug mode.

 -- : dbwhere
     In debugging mode, report the current file and line number where
     execution is stopped.

     See also: Note: dbstack, Note: dblist,
     Note: dbstatus, Note: dbcont, Note:
     dbstep, Note: dbup, Note: dbdown.

 -- : dbtype
 -- : dbtype LINENO
 -- : dbtype STARTL:ENDL
 -- : dbtype STARTL:END
 -- : dbtype FUNC
 -- : dbtype FUNC LINENO
 -- : dbtype FUNC STARTL:ENDL
 -- : dbtype FUNC STARTL:END
     Display a script file with line numbers.

     When called with no arguments in debugging mode, display the script
     file currently being debugged.

     An optional range specification can be used to list only a portion
     of the file.  The special keyword "end" is a valid line number
     specification for the last line of the file.

     When called with the name of a function, list that script file with
     line numbers.

     See also: Note: dblist, Note: dbwhere,
     Note: dbstatus, Note: dbstop.

 -- : dblist
 -- : dblist N
     In debugging mode, list N lines of the function being debugged
     centered around the current line to be executed.

     If unspecified N defaults to 10 (+/- 5 lines)

     See also: Note: dbwhere, Note: dbtype,
     Note: dbstack.

   You may also use ‘isdebugmode’ to determine whether the debugger is
currently active.

 -- : isdebugmode ()
     Return true if in debugging mode, otherwise false.

     See also: Note: dbwhere, Note: dbstack,
     Note: dbstatus.

   Debug mode also allows single line stepping through a function using
the command ‘dbstep’.

 -- : dbstep
 -- : dbstep N
 -- : dbstep in
 -- : dbstep out
 -- : dbnext ...
     In debugging mode, execute the next N lines of code.

     If N is omitted, execute the next single line of code.  If the next
     line of code is itself defined in terms of an m-file remain in the
     existing function.

     Using ‘dbstep in’ will cause execution of the next line to step
     into any m-files defined on the next line.

     Using ‘dbstep out’ will cause execution to continue until the
     current function returns.

     ‘dbnext’ is an alias for ‘dbstep’.

     See also: Note: dbcont, Note: dbquit.

   When in debug mode the <RETURN> key will execute the last entered
command.  This is useful, for example, after hitting a breakpoint and
entering ‘dbstep’ once.  After that, one can advance line by line
through the code with only a single key stroke.