text: # encoding: utf-8
  """
  System command aliases.
  
  Authors:
  
  * Fernando Perez
  * Brian Granger
  """
  
  #-----------------------------------------------------------------------------
  #  Copyright (C) 2008-2011  The IPython Development Team
  #
  #  Distributed under the terms of the BSD License.
  #
  #  The full license is in the file COPYING.txt, distributed with this software.
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  import os
  import re
  import sys
  
  from traitlets.config.configurable import Configurable
  from IPython.core.error import UsageError
  
  from IPython.utils.py3compat import string_types
  from traitlets import List, Instance
  from IPython.utils.warn import error
  
  #-----------------------------------------------------------------------------
  # Utilities
  #-----------------------------------------------------------------------------
  
  # This is used as the pattern for calls to split_user_input.
  shell_line_split = re.compile(r'^(\s*)()(\S+)(.*$)')
  
  def default_aliases():
      """Return list of shell aliases to auto-define.
      """
      # Note: the aliases defined here should be safe to use on a kernel
      # regardless of what frontend it is attached to.  Frontends that use a
      # kernel in-process can define additional aliases that will only work in
      # their case.  For example, things like 'less' or 'clear' that manipulate
      # the terminal should NOT be declared here, as they will only work if the
      # kernel is running inside a true terminal, and not over the network.
  
      if os.name == 'posix':
          default_aliases = [('mkdir', 'mkdir'), ('rmdir', 'rmdir'),
                             ('mv', 'mv'), ('rm', 'rm'), ('cp', 'cp'),
                             ('cat', 'cat'),
                             ]
          # Useful set of ls aliases.  The GNU and BSD options are a little
          # different, so we make aliases that provide as similar as possible
          # behavior in ipython, by passing the right flags for each platform
          if sys.platform.startswith('linux'):
              ls_aliases = [('ls', 'ls -F --color'),
                            # long ls
                            ('ll', 'ls -F -o --color'),
                            # ls normal files only
                            ('lf', 'ls -F -o --color %l | grep ^-'),
                            # ls symbolic links
                            ('lk', 'ls -F -o --color %l | grep ^l'),
                            # directories or links to directories,
                            ('ldir', 'ls -F -o --color %l | grep /$'),
                            # things which are executable
                            ('lx', 'ls -F -o --color %l | grep ^-..x'),
                            ]
          elif sys.platform.startswith('openbsd') or sys.platform.startswith('netbsd'):
              # OpenBSD, NetBSD. The ls implementation on these platforms do not support
              # the -G switch and lack the ability to use colorized output.
              ls_aliases = [('ls', 'ls -F'),
                            # long ls
                            ('ll', 'ls -F -l'),
                            # ls normal files only
                            ('lf', 'ls -F -l %l | grep ^-'),
                            # ls symbolic links
                            ('lk', 'ls -F -l %l | grep ^l'),
                            # directories or links to directories,
                            ('ldir', 'ls -F -l %l | grep /$'),
                            # things which are executable
                            ('lx', 'ls -F -l %l | grep ^-..x'),
                            ]
          else:
              # BSD, OSX, etc.
              ls_aliases = [('ls', 'ls -F -G'),
                            # long ls
                            ('ll', 'ls -F -l -G'),
                            # ls normal files only
                            ('lf', 'ls -F -l -G %l | grep ^-'),
                            # ls symbolic links
                            ('lk', 'ls -F -l -G %l | grep ^l'),
                            # directories or links to directories,
                            ('ldir', 'ls -F -G -l %l | grep /$'),
                            # things which are executable
                            ('lx', 'ls -F -l -G %l | grep ^-..x'),
                            ]
          default_aliases = default_aliases + ls_aliases
      elif os.name in ['nt', 'dos']:
          default_aliases = [('ls', 'dir /on'),
                             ('ddir', 'dir /ad /on'), ('ldir', 'dir /ad /on'),
                             ('mkdir', 'mkdir'), ('rmdir', 'rmdir'),
                             ('echo', 'echo'), ('ren', 'ren'), ('copy', 'copy'),
                             ]
      else:
          default_aliases = []
  
      return default_aliases
  
  
  class AliasError(Exception):
      pass
  
  
  class InvalidAliasError(AliasError):
      pass
  
  class Alias(object):
      """Callable object storing the details of one alias.
  
      Instances are registered as magic functions to allow use of aliases.
      """
  
      # Prepare blacklist
      blacklist = {'cd','popd','pushd','dhist','alias','unalias'}
  
      def __init__(self, shell, name, cmd):
          self.shell = shell
          self.name = name
          self.cmd = cmd
          self.nargs = self.validate()
  
      def validate(self):
          """Validate the alias, and return the number of arguments."""
          if self.name in self.blacklist:
              raise InvalidAliasError("The name %s can't be aliased "
                                      "because it is a keyword or builtin." % self.name)
          try:
              caller = self.shell.magics_manager.magics['line'][self.name]
          except KeyError:
              pass
          else:
              if not isinstance(caller, Alias):
                  raise InvalidAliasError("The name %s can't be aliased "
                                          "because it is another magic command." % self.name)
  
          if not (isinstance(self.cmd, string_types)):
              raise InvalidAliasError("An alias command must be a string, "
                                      "got: %r" % self.cmd)
  
          nargs = self.cmd.count('%s') - self.cmd.count('%%s')
    
          if (nargs > 0) and (self.cmd.find('%l') >= 0):
              raise InvalidAliasError('The %s and %l specifiers are mutually '
                                      'exclusive in alias definitions.')
  
          return nargs
  
      def __repr__(self):
          return "<alias {} for {!r}>".format(self.name, self.cmd)
  
      def __call__(self, rest=''):
          cmd = self.cmd
          nargs = self.nargs
          # Expand the %l special to be the user's input line
          if cmd.find('%l') >= 0:
              cmd = cmd.replace('%l', rest)
              rest = ''
          
          if nargs==0:
              if cmd.find('%%s') >= 1:
                  cmd = cmd.replace('%%s', '%s')
              # Simple, argument-less aliases
              cmd = '%s %s' % (cmd, rest)
          else:
              # Handle aliases with positional arguments
              args = rest.split(None, nargs)
              if len(args) < nargs:
                  raise UsageError('Alias <%s> requires %s arguments, %s given.' %
                        (self.name, nargs, len(args)))
              cmd = '%s %s' % (cmd % tuple(args[:nargs]),' '.join(args[nargs:]))
  
          self.shell.system(cmd)
  
  #-----------------------------------------------------------------------------
  # Main AliasManager class
  #-----------------------------------------------------------------------------
  
  class AliasManager(Configurable):
  
      default_aliases = List(default_aliases(), config=True)
      user_aliases = List(default_value=[], config=True)
      shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
  
      def __init__(self, shell=None, **kwargs):
          super(AliasManager, self).__init__(shell=shell, **kwargs)
          # For convenient access
          self.linemagics = self.shell.magics_manager.magics['line']
          self.init_aliases()
  
      def init_aliases(self):
          # Load default & user aliases
          for name, cmd in self.default_aliases + self.user_aliases:
              self.soft_define_alias(name, cmd)
  
      @property
      def aliases(self):
          return [(n, func.cmd) for (n, func) in self.linemagics.items()
                              if isinstance(func, Alias)]
  
      def soft_define_alias(self, name, cmd):
          """Define an alias, but don't raise on an AliasError."""
          try:
              self.define_alias(name, cmd)
          except AliasError as e:
              error("Invalid alias: %s" % e)
  
      def define_alias(self, name, cmd):
          """Define a new alias after validating it.
  
          This will raise an :exc:`AliasError` if there are validation
          problems.
          """
          caller = Alias(shell=self.shell, name=name, cmd=cmd)
          self.shell.magics_manager.register_function(caller, magic_kind='line',
                                                      magic_name=name)
  
      def get_alias(self, name):
          """Return an alias, or None if no alias by that name exists."""
          aname = self.linemagics.get(name, None)
          return aname if isinstance(aname, Alias) else None
  
      def is_alias(self, name):
          """Return whether or not a given name has been defined as an alias"""
          return self.get_alias(name) is not None
  
      def undefine_alias(self, name):
          if self.is_alias(name):
              del self.linemagics[name]
          else:
              raise ValueError('%s is not an alias' % name)
  
      def clear_aliases(self):
          for name, cmd in self.aliases:
              self.undefine_alias(name)
  
      def retrieve_alias(self, name):
          """Retrieve the command to which an alias expands."""
          caller = self.get_alias(name)
          if caller:
              return caller.cmd
          else:
              raise ValueError('%s is not an alias' % name)
  