zeroinstall/injector/run.py

   1 import os, sys
   2 from logging import debug, info
   3
   4 from model import Interface, SafeException, EnvironmentBinding
   5
   6 def do_env_binding(binding, path):
   7         extra = os.path.join(path, binding.insert)
   8         if binding.name in os.environ:
   9                 os.environ[binding.name] = extra + ':' + os.environ[binding.name]
  10         else:
  11                 os.environ[binding.name] = extra
  12         info("%s=%s", binding.name, os.environ[binding.name])
  13
  14 def execute(policy, prog_args, dry_run = False, main = None):
  15         iface = policy.get_interface(policy.root)
  16         if main is None and not iface.main:
  17                 raise SafeException("Interface '%s' cannot be executed directly; it is just a library "
  18                                     "to be used by other programs (or missing 'main' attribute on the "
  19                                     "root <interface> element)." % iface.name)
  20
  21         def setup_bindings(i):
  22                 impl = policy.get_implementation(i)
  23                 for dep in impl.dependencies.values():
  24                         dep_iface = policy.get_interface(dep.interface)
  25                         for b in dep.bindings:
  26                                 if isinstance(b, EnvironmentBinding):
  27                                         dep_impl = policy.get_implementation(dep_iface)
  28                                         do_env_binding(b, policy.get_implementation_path(dep_impl))
  29                         setup_bindings(dep_iface)
  30         setup_bindings(iface)
  31
  32         root_impl = policy.get_implementation(iface)
  33         if main is None:
  34                 main = iface.main
  35         elif main.startswith('/'):
  36                 main = main[1:]
  37         elif iface.main:
  38                 main = os.path.join(os.path.dirname(iface.main), main)
  39         prog_path = os.path.join(policy.get_implementation_path(root_impl), main)
  40         if not os.path.exists(prog_path):
  41                 raise SafeException("File '%s' does not exist.\n"
  42                                 "(implementation '%s' + program '%s')" %
  43                                 (prog_path, policy.implementation[iface].id, main))
  44         if dry_run:
  45                 print "Would execute:", prog_path
  46         else:
  47                 info("Executing: %s", prog_path)
  48                 sys.stdout.flush()
  49                 sys.stderr.flush()
  50                 os.execl(prog_path, prog_path, *prog_args)