#! /usr/bin/env python



"""A Python debugger."""



# (See pdb.doc for documentation.)



import sys

import linecache

import cmd

import bdb

from repr import Repr

import os

import re

import pprint

import traceback





class Restart(Exception):

    """Causes a debugger to be restarted for the debugged python program."""

    pass



# Create a custom safe Repr instance and increase its maxstring.

# The default of 30 truncates error messages too easily.

_repr = Repr()

_repr.maxstring = 200

_saferepr = _repr.repr



__all__ = ["run", "pm", "Pdb", "runeval", "runctx", "runcall", "set_trace",

           "post_mortem", "help"]



def find_function(funcname, filename):

    cre = re.compile(r'def\s+%s\s*[(]' % re.escape(funcname))

    try:

        fp = open(filename)

    except IOError:

        return None

    # consumer of this info expects the first line to be 1

    lineno = 1

    answer = None

    while 1:

        line = fp.readline()

        if line == '':

            break

        if cre.match(line):

            answer = funcname, filename, lineno

            break

        lineno = lineno + 1

    fp.close()

    return answer





# Interaction prompt line will separate file and call info from code

# text using value of line_prefix string.  A newline and arrow may

# be to your liking.  You can set it once pdb is imported using the

# command "pdb.line_prefix = '\n% '".

# line_prefix = ': '    # Use this to get the old situation back

line_prefix = '\n-> '   # Probably a better default



class Pdb(bdb.Bdb, cmd.Cmd):



    def __init__(self, completekey='tab', stdin=None, stdout=None):

        bdb.Bdb.__init__(self)

        cmd.Cmd.__init__(self, completekey, stdin, stdout)

        if stdout:

            self.use_rawinput = 0

        self.prompt = '(Pdb) '

        self.aliases = {}

        self.mainpyfile = ''

        self._wait_for_mainpyfile = 0

        # Try to load readline if it exists

        try:

            import readline

        except ImportError:

            pass



        # Read $HOME/.pdbrc and ./.pdbrc

        self.rcLines = []

        if 'HOME' in os.environ:

            envHome = os.environ['HOME']

            try:

                rcFile = open(os.path.join(envHome, ".pdbrc"))

            except IOError:

                pass

            else:

                for line in rcFile.readlines():

                    self.rcLines.append(line)

                rcFile.close()

        try:

            rcFile = open(".pdbrc")

        except IOError:

            pass

        else:

            for line in rcFile.readlines():

                self.rcLines.append(line)

            rcFile.close()



        self.commands = {} # associates a command list to breakpoint numbers

        self.commands_doprompt = {} # for each bp num, tells if the prompt must be disp. after execing the cmd list

        self.commands_silent = {} # for each bp num, tells if the stack trace must be disp. after execing the cmd list

        self.commands_defining = False # True while in the process of defining a command list

        self.commands_bnum = None # The breakpoint number for which we are defining a list



    def reset(self):

        bdb.Bdb.reset(self)

        self.forget()



    def forget(self):

        self.lineno = None

        self.stack = []

        self.curindex = 0

        self.curframe = None



    def setup(self, f, t):

        self.forget()

        self.stack, self.curindex = self.get_stack(f, t)

        self.curframe = self.stack[self.curindex][0]

        self.execRcLines()



    # Can be executed earlier than 'setup' if desired

    def execRcLines(self):

        if self.rcLines:

            # Make local copy because of recursion

            rcLines = self.rcLines

            # executed only once

            self.rcLines = []

            for line in rcLines:

                line = line[:-1]

                if len(line) > 0 and line[0] != '#':

                    self.onecmd(line)



    # Override Bdb methods



    def user_call(self, frame, argument_list):

        """This method is called when there is the remote possibility

        that we ever need to stop in this function."""

        if self._wait_for_mainpyfile:

            return

        if self.stop_here(frame):

            print >>self.stdout, '--Call--'

            self.interaction(frame, None)



    def user_line(self, frame):

        """This function is called when we stop or break at this line."""

        if self._wait_for_mainpyfile:

            if (self.mainpyfile != self.canonic(frame.f_code.co_filename)

                or frame.f_lineno<= 0):

                return

            self._wait_for_mainpyfile = 0

        if self.bp_commands(frame):

            self.interaction(frame, None)



    def bp_commands(self,frame):

        """ Call every command that was set for the current active breakpoint (if there is one)

        Returns True if the normal interaction function must be called, False otherwise """

        #self.currentbp is set in bdb.py in bdb.break_here if a breakpoint was hit

        if getattr(self,"currentbp",False) and self.currentbp in self.commands:

            currentbp = self.currentbp

            self.currentbp = 0

            lastcmd_back = self.lastcmd

            self.setup(frame, None)

            for line in self.commands[currentbp]:

                self.onecmd(line)

            self.lastcmd = lastcmd_back

            if not self.commands_silent[currentbp]:

                self.print_stack_entry(self.stack[self.curindex])

            if self.commands_doprompt[currentbp]:

                self.cmdloop()

            self.forget()

            return

        return 1



    def user_return(self, frame, return_value):

        """This function is called when a return trap is set here."""

        frame.f_locals['__return__'] = return_value

        print >>self.stdout, '--Return--'

        self.interaction(frame, None)



    def user_exception(self, frame, exc_info):

        exc_type, exc_value, exc_traceback = exc_info

        """This function is called if an exception occurs,

        but only if we are to stop at or just below this level."""

        frame.f_locals['__exception__'] = exc_type, exc_value

        if type(exc_type) == type(''):

            exc_type_name = exc_type

        else: exc_type_name = exc_type.__name__

        print >>self.stdout, exc_type_name + ':', _saferepr(exc_value)

        self.interaction(frame, exc_traceback)



    # General interaction function



    def interaction(self, frame, traceback):

        self.setup(frame, traceback)

        self.print_stack_entry(self.stack[self.curindex])

        self.cmdloop()

        self.forget()



    def displayhook(self, obj):

        """Custom displayhook for the exec in default(), which prevents

        assignment of the _ variable in the builtins.

        """

        print repr(obj)



    def default(self, line):

        if line[:1] == '!': line = line[1:]

        locals = self.curframe.f_locals

        globals = self.curframe.f_globals

        try:

            code = compile(line + '\n', '<stdin>', 'single')

            save_stdout = sys.stdout

            save_stdin = sys.stdin

            save_displayhook = sys.displayhook

            try:

                sys.stdin = self.stdin

                sys.stdout = self.stdout

                sys.displayhook = self.displayhook

                exec code in globals, locals

            finally:

                sys.stdout = save_stdout

                sys.stdin = save_stdin

                sys.displayhook = save_displayhook

        except:

            t, v = sys.exc_info()[:2]

            if type(t) == type(''):

                exc_type_name = t

            else: exc_type_name = t.__name__

            print >>self.stdout, '***', exc_type_name + ':', v



    def precmd(self, line):

        """Handle alias expansion and ';;' separator."""

        if not line.strip():

            return line

        args = line.split()

        while args[0] in self.aliases:

            line = self.aliases[args[0]]

            ii = 1

            for tmpArg in args[1:]:

                line = line.replace("%" + str(ii),

                                      tmpArg)

                ii = ii + 1

            line = line.replace("%*", ' '.join(args[1:]))

            args = line.split()

        # split into ';;' separated commands

        # unless it's an alias command

        if args[0] != 'alias':

            marker = line.find(';;')

            if marker >= 0:

                # queue up everything after marker

                next = line[marker+2:].lstrip()

                self.cmdqueue.append(next)

                line = line[:marker].rstrip()

        return line



    def onecmd(self, line):

        """Interpret the argument as though it had been typed in response

        to the prompt.



        Checks whether this line is typed at the normal prompt or in

        a breakpoint command list definition.

        """

        if not self.commands_defining:

            return cmd.Cmd.onecmd(self, line)

        else:

            return self.handle_command_def(line)



    def handle_command_def(self,line):

        """ Handles one command line during command list definition. """

        cmd, arg, line = self.parseline(line)

        if cmd == 'silent':

            self.commands_silent[self.commands_bnum] = True

            return # continue to handle other cmd def in the cmd list

        elif cmd == 'end':

            self.cmdqueue = []

            return 1 # end of cmd list

        cmdlist = self.commands[self.commands_bnum]

        if (arg):

            cmdlist.append(cmd+' '+arg)

        else:

            cmdlist.append(cmd)

        # Determine if we must stop

        try:

            func = getattr(self, 'do_' + cmd)

        except AttributeError:

            func = self.default

        if func.func_name in self.commands_resuming : # one of the resuming commands.

            self.commands_doprompt[self.commands_bnum] = False

            self.cmdqueue = []

            return 1

        return



    # Command definitions, called by cmdloop()

    # The argument is the remaining string on the command line

    # Return true to exit from the command loop



    do_h = cmd.Cmd.do_help



    def do_commands(self, arg):

        """Defines a list of commands associated to a breakpoint

        Those commands will be executed whenever the breakpoint causes the program to stop execution."""

        if not arg:

            bnum = len(bdb.Breakpoint.bpbynumber)-1

        else:

            try:

                bnum = int(arg)

            except:

                print >>self.stdout, "Usage : commands [bnum]\n        ...\n        end"

                return

        self.commands_bnum = bnum

        self.commands[bnum] = []

        self.commands_doprompt[bnum] = True

        self.commands_silent[bnum] = False

        prompt_back = self.prompt

        self.prompt = '(com) '

        self.commands_defining = True

        self.cmdloop()

        self.commands_defining = False

        self.prompt = prompt_back



    def do_break(self, arg, temporary = 0):

        # break [ ([filename:]lineno | function) [, "condition"] ]

        if not arg:

            if self.breaks:  # There's at least one

                print >>self.stdout, "Num Type         Disp Enb   Where"

                for bp in bdb.Breakpoint.bpbynumber:

                    if bp:

                        bp.bpprint(self.stdout)

            return

        # parse arguments; comma has lowest precedence

        # and cannot occur in filename

        filename = None

        lineno = None

        cond = None

        comma = arg.find(',')

        if comma > 0:

            # parse stuff after comma: "condition"

            cond = arg[comma+1:].lstrip()

            arg = arg[:comma].rstrip()

        # parse stuff before comma: [filename:]lineno | function

        colon = arg.rfind(':')

        funcname = None

        if colon >= 0:

            filename = arg[:colon].rstrip()

            f = self.lookupmodule(filename)

            if not f:

                print >>self.stdout, '*** ', repr(filename),

                print >>self.stdout, 'not found from sys.path'

                return

            else:

                filename = f

            arg = arg[colon+1:].lstrip()

            try:

                lineno = int(arg)

            except ValueError, msg:

                print >>self.stdout, '*** Bad lineno:', arg

                return

        else:

            # no colon; can be lineno or function

            try:

                lineno = int(arg)

            except ValueError:

                try:

                    func = eval(arg,

                                self.curframe.f_globals,

                                self.curframe.f_locals)

                except:

                    func = arg

                try:

                    if hasattr(func, 'im_func'):

                        func = func.im_func

                    code = func.func_code

                    #use co_name to identify the bkpt (function names

                    #could be aliased, but co_name is invariant)

                    funcname = code.co_name

                    lineno = code.co_firstlineno

                    filename = code.co_filename

                except:

                    # last thing to try

                    (ok, filename, ln) = self.lineinfo(arg)

                    if not ok:

                        print >>self.stdout, '*** The specified object',

                        print >>self.stdout, repr(arg),

                        print >>self.stdout, 'is not a function'

                        print >>self.stdout, 'or was not found along sys.path.'

                        return

                    funcname = ok # ok contains a function name

                    lineno = int(ln)

        if not filename:

            filename = self.defaultFile()

        # Check for reasonable breakpoint

        line = self.checkline(filename, lineno)

        if line:

            # now set the break point

            err = self.set_break(filename, line, temporary, cond, funcname)

            if err: print >>self.stdout, '***', err

            else:

                bp = self.get_breaks(filename, line)[-1]

                print >>self.stdout, "Breakpoint %d at %s:%d" % (bp.number,

                                                                 bp.file,

                                                                 bp.line)



    # To be overridden in derived debuggers

    def defaultFile(self):

        """Produce a reasonable default."""

        filename = self.curframe.f_code.co_filename

        if filename == '<string>' and self.mainpyfile:

            filename = self.mainpyfile

        return filename



    do_b = do_break



    def do_tbreak(self, arg):

        self.do_break(arg, 1)



    def lineinfo(self, identifier):

        failed = (None, None, None)

        # Input is identifier, may be in single quotes

        idstring = identifier.split("'")

        if len(idstring) == 1:

            # not in single quotes

            id = idstring[0].strip()

        elif len(idstring) == 3:

            # quoted

            id = idstring[1].strip()

        else:

            return failed

        if id == '': return failed

        parts = id.split('.')

        # Protection for derived debuggers

        if parts[0] == 'self':

            del parts[0]

            if len(parts) == 0:

                return failed

        # Best first guess at file to look at

        fname = self.defaultFile()

        if len(parts) == 1:

            item = parts[0]

        else:

            # More than one part.

            # First is module, second is method/class

            f = self.lookupmodule(parts[0])

            if f:

                fname = f

            item = parts[1]

        answer = find_function(item, fname)

        return answer or failed



    def checkline(self, filename, lineno):

        """Check whether specified line seems to be executable.



        Return `lineno` if it is, 0 if not (e.g. a docstring, comment, blank

        line or EOF). Warning: testing is not comprehensive.

        """

        line = linecache.getline(filename, lineno, self.curframe.f_globals)

        if not line:

            print >>self.stdout, 'End of file'

            return 0

        line = line.strip()

        # Don't allow setting breakpoint at a blank line

        if (not line or (line[0] == '#') or

             (line[:3] == '"""') or line[:3] == "'''"):

            print >>self.stdout, '*** Blank or comment'

            return 0

        return lineno



    def do_enable(self, arg):

        args = arg.split()

        for i in args:

            try:

                i = int(i)

            except ValueError:

                print >>self.stdout, 'Breakpoint index %r is not a number' % i

                continue



            if not (0 <= i < len(bdb.Breakpoint.bpbynumber)):

                print >>self.stdout, 'No breakpoint numbered', i

                continue



            bp = bdb.Breakpoint.bpbynumber[i]

            if bp:

                bp.enable()



    def do_disable(self, arg):

        args = arg.split()

        for i in args:

            try:

                i = int(i)

            except ValueError:

                print >>self.stdout, 'Breakpoint index %r is not a number' % i

                continue



            if not (0 <= i < len(bdb.Breakpoint.bpbynumber)):

                print >>self.stdout, 'No breakpoint numbered', i

                continue



            bp = bdb.Breakpoint.bpbynumber[i]

            if bp:

                bp.disable()



    def do_condition(self, arg):

        # arg is breakpoint number and condition

        args = arg.split(' ', 1)

        try:

            bpnum = int(args[0].strip())

        except ValueError:

            # something went wrong

            print >>self.stdout, \

                'Breakpoint index %r is not a number' % args[0]

            return

        try:

            cond = args[1]

        except:

            cond = None

        try:

            bp = bdb.Breakpoint.bpbynumber[bpnum]

        except IndexError:

            print >>self.stdout, 'Breakpoint index %r is not valid' % args[0]

            return

        if bp:

            bp.cond = cond

            if not cond:

                print >>self.stdout, 'Breakpoint', bpnum,

                print >>self.stdout, 'is now unconditional.'



    def do_ignore(self,arg):

        """arg is bp number followed by ignore count."""

        args = arg.split()

        try:

            bpnum = int(args[0].strip())

        except ValueError:

            # something went wrong

            print >>self.stdout, \

                'Breakpoint index %r is not a number' % args[0]

            return

        try:

            count = int(args[1].strip())

        except:

            count = 0

        try:

            bp = bdb.Breakpoint.bpbynumber[bpnum]

        except IndexError:

            print >>self.stdout, 'Breakpoint index %r is not valid' % args[0]

            return

        if bp:

            bp.ignore = count

            if count > 0:

                reply = 'Will ignore next '

                if count > 1:

                    reply = reply + '%d crossings' % count

                else:

                    reply = reply + '1 crossing'

                print >>self.stdout, reply + ' of breakpoint %d.' % bpnum

            else:

                print >>self.stdout, 'Will stop next time breakpoint',

                print >>self.stdout, bpnum, 'is reached.'



    def do_clear(self, arg):

        """Three possibilities, tried in this order:

        clear -> clear all breaks, ask for confirmation

        clear file:lineno -> clear all breaks at file:lineno

        clear bpno bpno ... -> clear breakpoints by number"""

        if not arg:

            try:

                reply = raw_input('Clear all breaks? ')

            except EOFError:

                reply = 'no'

            reply = reply.strip().lower()

            if reply in ('y', 'yes'):

                self.clear_all_breaks()

            return

        if ':' in arg:

            # Make sure it works for "clear C:\foo\bar.py:12"

            i = arg.rfind(':')

            filename = arg[:i]

            arg = arg[i+1:]

            try:

                lineno = int(arg)

            except ValueError:

                err = "Invalid line number (%s)" % arg

            else:

                err = self.clear_break(filename, lineno)

            if err: print >>self.stdout, '***', err

            return

        numberlist = arg.split()

        for i in numberlist:

            try:

                i = int(i)

            except ValueError:

                print >>self.stdout, 'Breakpoint index %r is not a number' % i

                continue



            if not (0 <= i < len(bdb.Breakpoint.bpbynumber)):

                print >>self.stdout, 'No breakpoint numbered', i

                continue

            err = self.clear_bpbynumber(i)

            if err:

                print >>self.stdout, '***', err

            else:

                print >>self.stdout, 'Deleted breakpoint', i

    do_cl = do_clear # 'c' is already an abbreviation for 'continue'



    def do_where(self, arg):

        self.print_stack_trace()

    do_w = do_where

    do_bt = do_where



    def do_up(self, arg):

        if self.curindex == 0:

            print >>self.stdout, '*** Oldest frame'

        else:

            self.curindex = self.curindex - 1

            self.curframe = self.stack[self.curindex][0]

            self.print_stack_entry(self.stack[self.curindex])

            self.lineno = None

    do_u = do_up



    def do_down(self, arg):

        if self.curindex + 1 == len(self.stack):

            print >>self.stdout, '*** Newest frame'

        else:

            self.curindex = self.curindex + 1

            self.curframe = self.stack[self.curindex][0]

            self.print_stack_entry(self.stack[self.curindex])

            self.lineno = None

    do_d = do_down



    def do_until(self, arg):

        self.set_until(self.curframe)

        return 1

    do_unt = do_until



    def do_step(self, arg):

        self.set_step()

        return 1

    do_s = do_step



    def do_next(self, arg):

        self.set_next(self.curframe)

        return 1

    do_n = do_next



    def do_run(self, arg):

        """Restart program by raising an exception to be caught in the main debugger

        loop. If arguments were given, set them in sys.argv."""

        if arg:

            import shlex

            argv0 = sys.argv[0:1]

            sys.argv = shlex.split(arg)

            sys.argv[:0] = argv0

        raise Restart



    do_restart = do_run



    def do_return(self, arg):

        self.set_return(self.curframe)

        return 1

    do_r = do_return



    def do_continue(self, arg):

        self.set_continue()

        return 1

    do_c = do_cont = do_continue



    def do_jump(self, arg):

        if self.curindex + 1 != len(self.stack):

            print >>self.stdout, "*** You can only jump within the bottom frame"

            return

        try:

            arg = int(arg)

        except ValueError:

            print >>self.stdout, "*** The 'jump' command requires a line number."

        else:

            try:

                # Do the jump, fix up our copy of the stack, and display the

                # new position

                self.curframe.f_lineno = arg

                self.stack[self.curindex] = self.stack[self.curindex][0], arg

                self.print_stack_entry(self.stack[self.curindex])

            except ValueError, e:

                print >>self.stdout, '*** Jump failed:', e

    do_j = do_jump



    def do_debug(self, arg):

        sys.settrace(None)

        globals = self.curframe.f_globals

        locals = self.curframe.f_locals

        p = Pdb(self.completekey, self.stdin, self.stdout)

        p.prompt = "(%s) " % self.prompt.strip()

        print >>self.stdout, "ENTERING RECURSIVE DEBUGGER"

        sys.call_tracing(p.run, (arg, globals, locals))

        print >>self.stdout, "LEAVING RECURSIVE DEBUGGER"

        sys.settrace(self.trace_dispatch)

        self.lastcmd = p.lastcmd



    def do_quit(self, arg):

        self._user_requested_quit = 1

        self.set_quit()

        return 1



    do_q = do_quit

    do_exit = do_quit



    def do_EOF(self, arg):

        print >>self.stdout

        self._user_requested_quit = 1

        self.set_quit()

        return 1



    def do_args(self, arg):

        f = self.curframe

        co = f.f_code

        dict = f.f_locals

        n = co.co_argcount

        if co.co_flags & 4: n = n+1

        if co.co_flags & 8: n = n+1

        for i in range(n):

            name = co.co_varnames[i]

            print >>self.stdout, name, '=',

            if name in dict: print >>self.stdout, dict[name]

            else: print >>self.stdout, "*** undefined ***"

    do_a = do_args



    def do_retval(self, arg):

        if '__return__' in self.curframe.f_locals:

            print >>self.stdout, self.curframe.f_locals['__return__']

        else:

            print >>self.stdout, '*** Not yet returned!'

    do_rv = do_retval



    def _getval(self, arg):

        try:

            return eval(arg, self.curframe.f_globals,

                        self.curframe.f_locals)

        except:

            t, v = sys.exc_info()[:2]

            if isinstance(t, str):

                exc_type_name = t

            else: exc_type_name = t.__name__

            print >>self.stdout, '***', exc_type_name + ':', repr(v)

            raise



    def do_p(self, arg):

        try:

            print >>self.stdout, repr(self._getval(arg))

        except:

            pass



    def do_pp(self, arg):

        try:

            pprint.pprint(self._getval(arg), self.stdout)

        except:

            pass



    def do_list(self, arg):

        self.lastcmd = 'list'

        last = None

        if arg:

            try:

                x = eval(arg, {}, {})

                if type(x) == type(()):

                    first, last = x

                    first = int(first)

                    last = int(last)

                    if last < first:

                        # Assume it's a count

                        last = first + last

                else:

                    first = max(1, int(x) - 5)

            except:

                print >>self.stdout, '*** Error in argument:', repr(arg)

                return

        elif self.lineno is None:

            first = max(1, self.curframe.f_lineno - 5)

        else:

            first = self.lineno + 1

        if last is None:

            last = first + 10

        filename = self.curframe.f_code.co_filename

        breaklist = self.get_file_breaks(filename)

        try:

            for lineno in range(first, last+1):

                line = linecache.getline(filename, lineno, self.curframe.f_globals)

                if not line:

                    print >>self.stdout, '[EOF]'

                    break

                else:

                    s = repr(lineno).rjust(3)

                    if len(s) < 4: s = s + ' '

                    if lineno in breaklist: s = s + 'B'

                    else: s = s + ' '

                    if lineno == self.curframe.f_lineno:

                        s = s + '->'

                    print >>self.stdout, s + '\t' + line,

                    self.lineno = lineno

        except KeyboardInterrupt:

            pass

    do_l = do_list



    def do_whatis(self, arg):

        try:

            value = eval(arg, self.curframe.f_globals,

                            self.curframe.f_locals)

        except:

            t, v = sys.exc_info()[:2]

            if type(t) == type(''):

                exc_type_name = t

            else: exc_type_name = t.__name__

            print >>self.stdout, '***', exc_type_name + ':', repr(v)

            return

        code = None

        # Is it a function?

        try: code = value.func_code

        except: pass

        if code:

            print >>self.stdout, 'Function', code.co_name

            return

        # Is it an instance method?

        try: code = value.im_func.func_code

        except: pass

        if code:

            print >>self.stdout, 'Method', code.co_name

            return

        # None of the above...

        print >>self.stdout, type(value)



    def do_alias(self, arg):

        args = arg.split()

        if len(args) == 0:

            keys = self.aliases.keys()

            keys.sort()

            for alias in keys:

                print >>self.stdout, "%s = %s" % (alias, self.aliases[alias])

            return

        if args[0] in self.aliases and len(args) == 1:

            print >>self.stdout, "%s = %s" % (args[0], self.aliases[args[0]])

        else:

            self.aliases[args[0]] = ' '.join(args[1:])



    def do_unalias(self, arg):

        args = arg.split()

        if len(args) == 0: return

        if args[0] in self.aliases:

            del self.aliases[args[0]]



    #list of all the commands making the program resume execution.

    commands_resuming = ['do_continue', 'do_step', 'do_next', 'do_return',

                         'do_quit', 'do_jump']



    # Print a traceback starting at the top stack frame.

    # The most recently entered frame is printed last;

    # this is different from dbx and gdb, but consistent with

    # the Python interpreter's stack trace.

    # It is also consistent with the up/down commands (which are

    # compatible with dbx and gdb: up moves towards 'main()'

    # and down moves towards the most recent stack frame).



    def print_stack_trace(self):

        try:

            for frame_lineno in self.stack:

                self.print_stack_entry(frame_lineno)

        except KeyboardInterrupt:

            pass



    def print_stack_entry(self, frame_lineno, prompt_prefix=line_prefix):

        frame, lineno = frame_lineno

        if frame is self.curframe:

            print >>self.stdout, '>',

        else:

            print >>self.stdout, ' ',

        print >>self.stdout, self.format_stack_entry(frame_lineno,

                                                     prompt_prefix)





    # Help methods (derived from pdb.doc)



    def help_help(self):

        self.help_h()



    def help_h(self):

        print >>self.stdout, """h(elp)

Without argument, print the list of available commands.

With a command name as argument, print help about that command

"help pdb" pipes the full documentation file to the $PAGER

"help exec" gives help on the ! command"""



    def help_where(self):

        self.help_w()



    def help_w(self):

        print >>self.stdout, """w(here)

Print a stack trace, with the most recent frame at the bottom.

An arrow indicates the "current frame", which determines the

context of most commands.  'bt' is an alias for this command."""



    help_bt = help_w



    def help_down(self):

        self.help_d()



    def help_d(self):

        print >>self.stdout, """d(own)

Move the current frame one level down in the stack trace

(to a newer frame)."""



    def help_up(self):

        self.help_u()



    def help_u(self):

        print >>self.stdout, """u(p)

Move the current frame one level up in the stack trace

(to an older frame)."""



    def help_break(self):

        self.help_b()



    def help_b(self):

        print >>self.stdout, """b(reak) ([file:]lineno | function) [, condition]

With a line number argument, set a break there in the current

file.  With a function name, set a break at first executable line

of that function.  Without argument, list all breaks.  If a second

argument is present, it is a string specifying an expression

which must evaluate to true before the breakpoint is honored.



The line number may be prefixed with a filename and a colon,

to specify a breakpoint in another file (probably one that

hasn't been loaded yet).  The file is searched for on sys.path;

the .py suffix may be omitted."""



    def help_clear(self):

        self.help_cl()



    def help_cl(self):

        print >>self.stdout, "cl(ear) filename:lineno"

        print >>self.stdout, """cl(ear) [bpnumber [bpnumber...]]

With a space separated list of breakpoint numbers, clear

those breakpoints.  Without argument, clear all breaks (but

first ask confirmation).  With a filename:lineno argument,

clear all breaks at that line in that file.



Note that the argument is different from previous versions of

the debugger (in python distributions 1.5.1 and before) where

a linenumber was used instead of either filename:lineno or

breakpoint numbers."""



    def help_tbreak(self):

        print >>self.stdout, """tbreak  same arguments as break, but breakpoint is

removed when first hit."""



    def help_enable(self):

        print >>self.stdout, """enable bpnumber [bpnumber ...]

Enables the breakpoints given as a space separated list of

bp numbers."""



    def help_disable(self):

        print >>self.stdout, """disable bpnumber [bpnumber ...]

Disables the breakpoints given as a space separated list of

bp numbers."""



    def help_ignore(self):

        print >>self.stdout, """ignore bpnumber count

Sets the ignore count for the given breakpoint number.  A breakpoint

becomes active when the ignore count is zero.  When non-zero, the

count is decremented each time the breakpoint is reached and the

breakpoint is not disabled and any associated condition evaluates

to true."""



    def help_condition(self):

        print >>self.stdout, """condition bpnumber str_condition

str_condition is a string specifying an expression which

must evaluate to true before the breakpoint is honored.

If str_condition is absent, any existing condition is removed;

i.e., the breakpoint is made unconditional."""



    def help_step(self):

        self.help_s()



    def help_s(self):

        print >>self.stdout, """s(tep)

Execute the current line, stop at the first possible occasion

(either in a function that is called or in the current function)."""



    def help_until(self):

        self.help_unt()



    def help_unt(self):

        print """unt(il)

Continue execution until the line with a number greater than the current

one is reached or until the current frame returns"""



    def help_next(self):

        self.help_n()



    def help_n(self):

        print >>self.stdout, """n(ext)

Continue execution until the next line in the current function

is reached or it returns."""



    def help_return(self):

        self.help_r()



    def help_r(self):

        print >>self.stdout, """r(eturn)

Continue execution until the current function returns."""



    def help_continue(self):

        self.help_c()



    def help_cont(self):

        self.help_c()



    def help_c(self):

        print >>self.stdout, """c(ont(inue))

Continue execution, only stop when a breakpoint is encountered."""



    def help_jump(self):

        self.help_j()



    def help_j(self):

        print >>self.stdout, """j(ump) lineno

Set the next line that will be executed."""



    def help_debug(self):

        print >>self.stdout, """debug code

Enter a recursive debugger that steps through the code argument

(which is an arbitrary expression or statement to be executed

in the current environment)."""



    def help_list(self):

        self.help_l()



    def help_l(self):

        print >>self.stdout, """l(ist) [first [,last]]

List source code for the current file.

Without arguments, list 11 lines around the current line

or continue the previous listing.

With one argument, list 11 lines starting at that line.

With two arguments, list the given range;

if the second argument is less than the first, it is a count."""



    def help_args(self):

        self.help_a()



    def help_a(self):

        print >>self.stdout, """a(rgs)

Print the arguments of the current function."""



    def help_p(self):

        print >>self.stdout, """p expression

Print the value of the expression."""



    def help_pp(self):

        print >>self.stdout, """pp expression

Pretty-print the value of the expression."""



    def help_exec(self):

        print >>self.stdout, """(!) statement

Execute the (one-line) statement in the context of

the current stack frame.

The exclamation point can be omitted unless the first word

of the statement resembles a debugger command.

To assign to a global variable you must always prefix the

command with a 'global' command, e.g.:

(Pdb) global list_options; list_options = ['-l']

(Pdb)"""



    def help_run(self):

        print """run [args...]

Restart the debugged python program. If a string is supplied, it is

splitted with "shlex" and the result is used as the new sys.argv.

History, breakpoints, actions and debugger options are preserved.

"restart" is an alias for "run"."""



    help_restart = help_run



    def help_quit(self):

        self.help_q()



    def help_q(self):

        print >>self.stdout, """q(uit) or exit - Quit from the debugger.

The program being executed is aborted."""



    help_exit = help_q



    def help_whatis(self):

        print >>self.stdout, """whatis arg

Prints the type of the argument."""



    def help_EOF(self):

        print >>self.stdout, """EOF

Handles the receipt of EOF as a command."""



    def help_alias(self):

        print >>self.stdout, """alias [name [command [parameter parameter ...] ]]

Creates an alias called 'name' the executes 'command'.  The command

must *not* be enclosed in quotes.  Replaceable parameters are

indicated by %1, %2, and so on, while %* is replaced by all the

parameters.  If no command is given, the current alias for name

is shown. If no name is given, all aliases are listed.



Aliases may be nested and can contain anything that can be

legally typed at the pdb prompt.  Note!  You *can* override

internal pdb commands with aliases!  Those internal commands

are then hidden until the alias is removed.  Aliasing is recursively

applied to the first word of the command line; all other words

in the line are left alone.



Some useful aliases (especially when placed in the .pdbrc file) are:



#Print instance variables (usage "pi classInst")

alias pi for k in %1.__dict__.keys(): print "%1.",k,"=",%1.__dict__[k]



#Print instance variables in self

alias ps pi self

"""



    def help_unalias(self):

        print >>self.stdout, """unalias name

Deletes the specified alias."""



    def help_commands(self):

        print >>self.stdout, """commands [bpnumber]

(com) ...

(com) end

(Pdb)



Specify a list of commands for breakpoint number bpnumber.  The

commands themselves appear on the following lines.  Type a line

containing just 'end' to terminate the commands.



To remove all commands from a breakpoint, type commands and

follow it immediately with  end; that is, give no commands.



With no bpnumber argument, commands refers to the last

breakpoint set.



You can use breakpoint commands to start your program up again.

Simply use the continue command, or step, or any other

command that resumes execution.



Specifying any command resuming execution (currently continue,

step, next, return, jump, quit and their abbreviations) terminates

the command list (as if that command was immediately followed by end).

This is because any time you resume execution

(even with a simple next or step), you may encounter

another breakpoint--which could have its own command list, leading to

ambiguities about which list to execute.



   If you use the 'silent' command in the command list, the

usual message about stopping at a breakpoint is not printed.  This may

be desirable for breakpoints that are to print a specific message and

then continue.  If none of the other commands print anything, you

see no sign that the breakpoint was reached.

"""



    def help_pdb(self):

        help()



    def lookupmodule(self, filename):

        """Helper function for break/clear parsing -- may be overridden.



        lookupmodule() translates (possibly incomplete) file or module name

        into an absolute file name.

        """

        if os.path.isabs(filename) and  os.path.exists(filename):

            return filename

        f = os.path.join(sys.path[0], filename)

        if  os.path.exists(f) and self.canonic(f) == self.mainpyfile:

            return f

        root, ext = os.path.splitext(filename)

        if ext == '':

            filename = filename + '.py'

        if os.path.isabs(filename):

            return filename

        for dirname in sys.path:

            while os.path.islink(dirname):

                dirname = os.readlink(dirname)

            fullname = os.path.join(dirname, filename)

            if os.path.exists(fullname):

                return fullname

        return None



    def _runscript(self, filename):

        # The script has to run in __main__ namespace (or imports from

        # __main__ will break).

        #

        # So we clear up the __main__ and set several special variables

        # (this gets rid of pdb's globals and cleans old variables on restarts).

        import __main__

        __main__.__dict__.clear()

        __main__.__dict__.update({"__name__"    : "__main__",

                                  "__file__"    : filename,

                                  "__builtins__": __builtins__,

                                 })



        # When bdb sets tracing, a number of call and line events happens

        # BEFORE debugger even reaches user's code (and the exact sequence of

        # events depends on python version). So we take special measures to

        # avoid stopping before we reach the main script (see user_line and

        # user_call for details).

        self._wait_for_mainpyfile = 1

        self.mainpyfile = self.canonic(filename)

        self._user_requested_quit = 0

        statement = 'execfile( "%s")' % filename

        self.run(statement)



# Simplified interface



def run(statement, globals=None, locals=None):

    Pdb().run(statement, globals, locals)



def runeval(expression, globals=None, locals=None):

    return Pdb().runeval(expression, globals, locals)



def runctx(statement, globals, locals):

    # B/W compatibility

    run(statement, globals, locals)



def runcall(*args, **kwds):

    return Pdb().runcall(*args, **kwds)



def set_trace():

    Pdb().set_trace(sys._getframe().f_back)



# Post-Mortem interface



def post_mortem(t=None):

    # handling the default

    if t is None:

        # sys.exc_info() returns (type, value, traceback) if an exception is

        # being handled, otherwise it returns None

        t = sys.exc_info()[2]

        if t is None:

            raise ValueError("A valid traceback must be passed if no "

                                               "exception is being handled")



    p = Pdb()

    p.reset()

    p.interaction(None, t)



def pm():

    post_mortem(sys.last_traceback)





# Main program for testing



TESTCMD = 'import x; x.main()'



def test():

    run(TESTCMD)



# print help

def help():

    for dirname in sys.path:

        fullname = os.path.join(dirname, 'pdb.doc')

        if os.path.exists(fullname):

            sts = os.system('${PAGER-more} '+fullname)

            if sts: print '*** Pager exit status:', sts

            break

    else:

        print 'Sorry, can\'t find the help file "pdb.doc"',

        print 'along the Python search path'



def main():

    if not sys.argv[1:] or sys.argv[1] in ("--help", "-h"):

        print "usage: pdb.py scriptfile [arg] ..."

        sys.exit(2)



    mainpyfile =  sys.argv[1]     # Get script filename

    if not os.path.exists(mainpyfile):

        print 'Error:', mainpyfile, 'does not exist'

        sys.exit(1)



    del sys.argv[0]         # Hide "pdb.py" from argument list



    # Replace pdb's dir with script's dir in front of module search path.

    sys.path[0] = os.path.dirname(mainpyfile)



    # Note on saving/restoring sys.argv: it's a good idea when sys.argv was

    # modified by the script being debugged. It's a bad idea when it was

    # changed by the user from the command line. There is a "restart" command which

    # allows explicit specification of command line arguments.

    pdb = Pdb()

    while 1:

        try:

            pdb._runscript(mainpyfile)

            if pdb._user_requested_quit:

                break

            print "The program finished and will be restarted"

        except Restart:

            print "Restarting", mainpyfile, "with arguments:"

            print "\t" + " ".join(sys.argv[1:])

        except SystemExit:

            # In most cases SystemExit does not warrant a post-mortem session.

            print "The program exited via sys.exit(). Exit status: ",

            print sys.exc_info()[1]

        except:

            traceback.print_exc()

            print "Uncaught exception. Entering post mortem debugging"

            print "Running 'cont' or 'step' will restart the program"

            t = sys.exc_info()[2]

            pdb.interaction(None, t)

            print "Post mortem debugger finished. The "+mainpyfile+" will be restarted"





# When invoked as main program, invoke the debugger on a script

if __name__ == '__main__':

    import pdb

    pdb.main()

