| # -*- coding: utf-8 -*- |
| # Copyright 2011 Google Inc. All Rights Reserved. |
| # Copyright 2011, Nexenta Systems 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. |
| """Implementation of Unix-like cat command for cloud storage providers.""" |
| |
| from __future__ import absolute_import |
| |
| import re |
| |
| from gslib.cat_helper import CatHelper |
| from gslib.command import Command |
| from gslib.command_argument import CommandArgument |
| from gslib.cs_api_map import ApiSelector |
| from gslib.exception import CommandException |
| from gslib.util import NO_MAX |
| |
| _SYNOPSIS = """ |
| gsutil cat [-h] url... |
| """ |
| |
| _DETAILED_HELP_TEXT = (""" |
| <B>SYNOPSIS</B> |
| """ + _SYNOPSIS + """ |
| |
| |
| <B>DESCRIPTION</B> |
| The cat command outputs the contents of one or more URLs to stdout. |
| It is equivalent to doing: |
| |
| gsutil cp url... - |
| |
| (The final '-' causes gsutil to stream the output to stdout.) |
| |
| |
| <B>WARNING: DATA INTEGRITY CHECKING NOT DONE</B> |
| The gsutil cat command does not compute a checksum of the downloaded data. |
| Therefore, we recommend that users either perform their own validation of the |
| output of gsutil cat or use gsutil cp or rsync (both of which perform |
| integrity checking automatically). |
| |
| |
| <B>OPTIONS</B> |
| -h Prints short header for each object. For example: |
| |
| gsutil cat -h gs://bucket/meeting_notes/2012_Feb/*.txt |
| |
| This would print a header with the object name before the contents |
| of each text object that matched the wildcard. |
| |
| -r range Causes gsutil to output just the specified byte range of the |
| object. Ranges are can be of these forms: |
| |
| start-end (e.g., -r 256-5939) |
| start- (e.g., -r 256-) |
| -numbytes (e.g., -r -5) |
| |
| where offsets start at 0, start-end means to return bytes start |
| through end (inclusive), start- means to return bytes start |
| through the end of the object, and -numbytes means to return the |
| last numbytes of the object. For example: |
| |
| gsutil cat -r 256-939 gs://bucket/object |
| |
| returns bytes 256 through 939, while: |
| |
| gsutil cat -r -5 gs://bucket/object |
| |
| returns the final 5 bytes of the object. |
| """) |
| |
| |
| class CatCommand(Command): |
| """Implementation of gsutil cat command.""" |
| |
| # Command specification. See base class for documentation. |
| command_spec = Command.CreateCommandSpec( |
| 'cat', |
| command_name_aliases=[], |
| usage_synopsis=_SYNOPSIS, |
| min_args=1, |
| max_args=NO_MAX, |
| supported_sub_args='hr:', |
| file_url_ok=False, |
| provider_url_ok=False, |
| urls_start_arg=0, |
| gs_api_support=[ApiSelector.XML, ApiSelector.JSON], |
| gs_default_api=ApiSelector.JSON, |
| argparse_arguments=[ |
| CommandArgument.MakeZeroOrMoreCloudURLsArgument() |
| ] |
| ) |
| # Help specification. See help_provider.py for documentation. |
| help_spec = Command.HelpSpec( |
| help_name='cat', |
| help_name_aliases=[], |
| help_type='command_help', |
| help_one_line_summary='Concatenate object content to stdout', |
| help_text=_DETAILED_HELP_TEXT, |
| subcommand_help_text={}, |
| ) |
| |
| # Command entry point. |
| def RunCommand(self): |
| """Command entry point for the cat command.""" |
| show_header = False |
| request_range = None |
| start_byte = 0 |
| end_byte = None |
| if self.sub_opts: |
| for o, a in self.sub_opts: |
| if o == '-h': |
| show_header = True |
| elif o == '-r': |
| request_range = a.strip() |
| range_matcher = re.compile( |
| '^(?P<start>[0-9]+)-(?P<end>[0-9]*)$|^(?P<endslice>-[0-9]+)$') |
| range_match = range_matcher.match(request_range) |
| if not range_match: |
| raise CommandException('Invalid range (%s)' % request_range) |
| if range_match.group('start'): |
| start_byte = long(range_match.group('start')) |
| if range_match.group('end'): |
| end_byte = long(range_match.group('end')) |
| if range_match.group('endslice'): |
| start_byte = long(range_match.group('endslice')) |
| else: |
| self.RaiseInvalidArgumentException() |
| |
| return CatHelper(self).CatUrlStrings(self.args, |
| show_header=show_header, |
| start_byte=start_byte, |
| end_byte=end_byte) |