Scripts to download files from google storage based on sha1 sums

third_party/gsutil/gslib/commands/help.py

+# Copyright 2011 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import gslib
+import itertools
+import os
+import re
+import struct
+import sys
+
+from gslib.command import Command
+from gslib.command import COMMAND_NAME
+from gslib.command import COMMAND_NAME_ALIASES
+from gslib.command import CONFIG_REQUIRED
+from gslib.command import FILE_URIS_OK
+from gslib.command import MAX_ARGS
+from gslib.command import MIN_ARGS
+from gslib.command import PROVIDER_URIS_OK
+from gslib.command import SUPPORTED_SUB_ARGS
+from gslib.command import URIS_START_ARG
+from gslib.exception import CommandException
+from gslib.help_provider import ALL_HELP_TYPES
+from gslib.help_provider import HELP_NAME
+from gslib.help_provider import HELP_NAME_ALIASES
+from gslib.help_provider import HELP_ONE_LINE_SUMMARY
+from gslib.help_provider import HelpProvider
+from gslib.help_provider import HELP_TEXT
+from gslib.help_provider import HelpType
+from gslib.help_provider import HELP_TYPE
+from gslib.help_provider import MAX_HELP_NAME_LEN
+from subprocess import PIPE
+from subprocess import Popen
+
+_detailed_help_text = ("""
+<B>SYNOPSIS</B>
+  gsutil help [command or topic]
+
+
+<B>DESCRIPTION</B>
+  Running:
+    gsutil help
+  will provide a summary of all commands and additional topics on which
+  help is available.
+
+  Running:
+    gsutil help command or topic
+  will provide help about the specified command or topic.
+
+  If you set the PAGER environment variable to the path to a pager program
+  (such as /bin/less on Linux), long help sections will be piped through
+  the specified pager.
+""")
+
+top_level_usage_string = (
+    "Usage: gsutil [-d][-D] [-h header]... [-m] [command [opts...] args...]"
+)
+
+class HelpCommand(Command):
+  """Implementation of gsutil help command."""
+
+  # Command specification (processed by parent class).
+  command_spec = {
+    # Name of command.
+    COMMAND_NAME : 'help',
+    # List of command name aliases.
+    COMMAND_NAME_ALIASES : ['?'],
+    # Min number of args required by this command.
+    MIN_ARGS : 0,
+    # Max number of args required by this command, or NO_MAX.
+    MAX_ARGS : 1,
+    # Getopt-style string specifying acceptable sub args.
+    SUPPORTED_SUB_ARGS : '',
+    # True if file URIs acceptable for this command.
+    FILE_URIS_OK : True,
+    # True if provider-only URIs acceptable for this command.
+    PROVIDER_URIS_OK : False,
+    # Index in args of first URI arg.
+    URIS_START_ARG : 0,
+    # True if must configure gsutil before running command.
+    CONFIG_REQUIRED : False,
+  }
+  help_spec = {
+    # Name of command or auxiliary help info for which this help applies.
+    HELP_NAME : 'help',
+    # List of help name aliases.
+    HELP_NAME_ALIASES : ['?'],
+    # Type of help:
+    HELP_TYPE : HelpType.COMMAND_HELP,
+    # One line summary of this help.
+    HELP_ONE_LINE_SUMMARY : 'Get help about commands and topics',
+    # The full help text.
+    HELP_TEXT : _detailed_help_text,
+  }
+
+  # Command entry point.
+  def RunCommand(self):
+    (help_type_map, help_name_map) = self._LoadHelpMaps()
+    output = []
+    if not len(self.args):
+      output.append('%s\nAvailable commands:\n' % top_level_usage_string)
+      format_str = '  %-' + str(MAX_HELP_NAME_LEN) + 's%s\n'
+      for help_prov in sorted(help_type_map[HelpType.COMMAND_HELP],
+                              key=lambda hp: hp.help_spec[HELP_NAME]):
+        output.append(format_str % (help_prov.help_spec[HELP_NAME],
+                                    help_prov.help_spec[HELP_ONE_LINE_SUMMARY]))
+      output.append('\nAdditional help topics:\n')
+      for help_prov in sorted(help_type_map[HelpType.ADDITIONAL_HELP],
+                              key=lambda hp: hp.help_spec[HELP_NAME]):
+        output.append(format_str % (help_prov.help_spec[HELP_NAME],
+                                    help_prov.help_spec[HELP_ONE_LINE_SUMMARY]))
+      output.append('\nUse gsutil help <command or topic> for detailed help.')
+    else:
+      arg = self.args[0]
+      if arg not in help_name_map:
+        output.append('No help available for "%s"' % arg)
+      else:
+        help_prov = help_name_map[self.args[0]]
+        output.append('<B>NAME</B>\n')
+        output.append('  %s - %s\n' % (
+          help_prov.help_spec[HELP_NAME],
+          help_prov.help_spec[HELP_ONE_LINE_SUMMARY]))
+        output.append('\n\n')
+        output.append(help_prov.help_spec[HELP_TEXT].strip('\n'))
+    self._OutputHelp(''.join(output))
+    return 0
+
+  def _OutputHelp(self, str):
+    """Outputs simply formatted string, paginating if long and PAGER defined"""
+    # Replace <B> and </B> with terminal formatting strings.
+    str = re.sub('<B>', '\033[1m', str)
+    str = re.sub('</B>', '\033[0;0m', str)
+    num_lines = len(str.split('\n'))
+    if 'PAGER' in os.environ and num_lines >= self.getTermLines():
+      # Use -r option for less to make bolding work right.
+      pager = os.environ['PAGER'].split(' ')
+      if pager[0].endswith('less'):
+        pager.append('-r')
+      try:
+        Popen(pager, stdin=PIPE).communicate(input=str)
+      except OSError, e:
+        raise CommandException('Unable to open pager (%s): %s' %
+            (' '.join(pager), e))
+    else:
+      print str
+
+  _DEFAULT_LINES = 25
+
+  def getTermLines(self):
+    """Returns number of terminal lines"""
+    # fcntl isn't supported in Windows.
+    try:
+      import fcntl
+      import termios
+    except ImportError:
+      return _DEFAULT_LINES
+    def ioctl_GWINSZ(fd):
+      try:
+        return struct.unpack(
+            'hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))[0]
+      except:
+        return 0 # Failure (so will retry on different file descriptor below).
+    # Try to find a valid number of lines from termio for stdin, stdout,
+    # or stderr, in that order.
+    ioc = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)
+    if not ioc:
+      try:
+        fd = os.open(os.ctermid(), os.O_RDONLY)
+        ioc = ioctl_GWINSZ(fd)
+        os.close(fd)
+      except:
+        pass
+    if not ioc:
+      if 'LINES' in os.environ:
+        ioc = env['LINES']
+      else:
+        ioc = _DEFAULT_LINES
+    return int(ioc)
+
+  def _LoadHelpMaps(self):
+    """Returns tuple (help type -> [HelpProviders],
+                      help name->HelpProvider dict,
+                     )."""
+    # Walk gslib/commands and gslib/addlhelp to find all HelpProviders.
+    for f in os.listdir(os.path.join(self.gsutil_bin_dir, 'gslib', 'commands')):
+      # Handles no-extension files, etc.
+      (module_name, ext) = os.path.splitext(f)
+      if ext == '.py':
+        __import__('gslib.commands.%s' % module_name)
+    for f in os.listdir(os.path.join(self.gsutil_bin_dir, 'gslib', 'addlhelp')):
+      (module_name, ext) = os.path.splitext(f)
+      if ext == '.py':
+        __import__('gslib.addlhelp.%s' % module_name)
+    help_type_map = {}
+    help_name_map = {}
+    for s in gslib.help_provider.ALL_HELP_TYPES:
+      help_type_map[s] = []
+    # Only include HelpProvider subclasses in the dict.
+    for help_prov in itertools.chain(
+        HelpProvider.__subclasses__(), Command.__subclasses__()):
+      if help_prov is Command:
+        # Skip the Command base class itself; we just want its subclasses,
+        # where the help command text lives (in addition to non-Command
+        # HelpProviders, like naming.py).
+        continue
+      gslib.help_provider.SanityCheck(help_prov, help_name_map)
+      help_name_map[help_prov.help_spec[HELP_NAME]] = help_prov
+      for help_name_aliases in help_prov.help_spec[HELP_NAME_ALIASES]:
+        help_name_map[help_name_aliases] = help_prov
+      help_type_map[help_prov.help_spec[HELP_TYPE]].append(help_prov)
+    return (help_type_map, help_name_map)