Package osh :: Module api
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Source Code for Module osh.api

  1  # osh 
  2  # Copyright (C) 2005 Jack Orenstein <jao@geophile.com> 
  3  # 
  4  # This program is free software; you can redistribute it and/or modify 
  5  # it under the terms of the GNU General Public License as published by 
  6  # the Free Software Foundation; either version 2 of the License, or 
  7  # (at your option) any later version. 
  8  # 
  9  # This program is distributed in the hope that it will be useful, 
 10  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 11  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 12  # GNU General Public License for more details. 
 13  # 
 14  # You should have received a copy of the GNU General Public License 
 15  # along with this program; if not, write to the Free Software 
 16  # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 17   
 18  """The osh API (Application Programming Interface) supports the use of osh from Python code. 
 19  The recommended form of import is C{from osh.api import *}. This imports 
 20  the functions documented here as well as 
 21  the symbols from the module C{osh.builtins}, 
 22  the C{Process} class, and C{processes} 
 23  function. 
 24   
 25  In general, the function C{F()} can be found in the module 
 26  C{osh.command.F}. See documentation for the package osh.command for 
 27  information on each function. 
 28  """ 
 29   
 30  import sys 
 31  import types 
 32   
 33  from args import Option 
 34  import apiparser 
 35  import core 
 36  import config 
 37  import error 
 38  import command 
 39  import command.f 
 40  from builtins import * 
 41   
42 -def _import_package(package_name):
43 package = globals()[package_name] 44 for module_name in package.__all__: 45 exec('import %s.%s' % (package_name, module_name)) 46 mod = getattr(package, module_name) 47 for element_name in dir(mod): 48 if not element_name.startswith('_'): 49 element = getattr(mod, element_name) 50 if type(element) is types.FunctionType: 51 globals()[element_name] = element
52 53 54 # Top-level api invocation 55
56 -def osh(*ops):
57 """Invoke osh interpreter. Each argument is a function invocation identifying a command. 58 The command sequence corresponds to the sequence of arguments. 59 """ 60 # Do we need to accumulate output? 61 output_accumulator = None 62 if (ops[-1].__class__ is _ReturnList): 63 output_accumulator = [] 64 ops = ops[:-1] 65 # Construct the pipeline 66 pipeline = None 67 try: 68 pipeline = apiparser._sequence_op(ops) 69 except Exception, e: 70 print >>sys.stderr, e 71 sys.exit(1) 72 # Append accumulator if we're accumulating output 73 if output_accumulator is not None: 74 pipeline.append_op(f(lambda *x: output_accumulator.append(x))) 75 # Run 76 pipeline.setup() 77 if core.verbosity >= 1: 78 print pipeline.dump() 79 try: 80 pipeline.execute() 81 except error.ExceptionHandlerException, e: 82 raise e.cause 83 return output_accumulator
84 85 86 # If present as last argument to osh(), return_list() indicates that we should accumulate output 87 # and return it in a list. 88
89 -class _ReturnList(object):
90 pass
91
92 -def return_list():
93 """Input tuples are accumulated in a list which is returned as the value of the 94 C{osh()} invocation. 95 """ 96 return _ReturnList()
97 98 99 # Error and exception handling 100
101 -def set_error_handler(handler):
102 """Replaces the standard error handler (which prints to stderr). An error handler 103 takes these arguments: 104 - C{line}: A line printed to stderr by the failing operation. 105 - C{op}: The failing operation. 106 - C{input}: The input to the failing operation. 107 - C{host}: The host on which the error occurred (in case of remote execution). 108 """ 109 error.set_error_handler(handler)
110
111 -def set_exception_handler(handler):
112 """Replaces the standard exception handler (which prints to stderr). An exception handler 113 takes these arguments: 114 - C{exception}: The exception being handled. 115 - C{op}: The operation that caused the exception. 116 - C{input}: The input to the operation that caused the exception. 117 - C{host}: The host on which the exception occurred (in case of remote execution). 118 """ 119 error.set_exception_handler(handler)
120 121 122 # Debugging 123
124 -def debug(verbosity):
125 """Control osh debugging: 0 = off, 1 = parse tree, 2 = command execution. 126 """ 127 core.verbosity = verbosity
128 129 130 # Setup 131 132 _import_package('command') 133