Use new common tools in Python scripts

tools/misc_utils.py

 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
-"""Module to host the VerboseSubprocess, ChangeDir, and ReSearch classes.
-"""
-
-import os
-import re
-import subprocess
+"""Miscellaneous utilities."""
 
 
-def print_subprocess_args(prefix, *args, **kwargs):
-    """Print out args in a human-readable manner."""
-    def quote_and_escape(string):
-        """Quote and escape a string if necessary."""
-        if ' ' in string or '\n' in string:
-            string = '"%s"' % string.replace('"', '\\"')
-        return string
-    if 'cwd' in kwargs:
-        print '%scd %s' % (prefix, kwargs['cwd'])
-    print prefix + ' '.join(quote_and_escape(arg) for arg in args[0])
-    if 'cwd' in kwargs:
-        print '%scd -' % prefix
-
-
-class VerboseSubprocess(object):
-    """Call subprocess methods, but print out command before executing.
-
-    Attributes:
-        verbose: (boolean) should we print out the command or not.  If
-                 not, this is the same as calling the subprocess method
-        quiet: (boolean) suppress stdout on check_call and call.
-        prefix: (string) When verbose, what to print before each command.
-    """
-
-    def __init__(self, verbose):
-        self.verbose = verbose
-        self.quiet = not verbose
-        self.prefix = '~~$ '
-
-    def check_call(self, *args, **kwargs):
-        """Wrapper for subprocess.check_call().
-
-        Args:
-            *args: to be passed to subprocess.check_call()
-            **kwargs: to be passed to subprocess.check_call()
-        Returns:
-            Whatever subprocess.check_call() returns.
-        Raises:
-            OSError or subprocess.CalledProcessError: raised by check_call.
-        """
-        if self.verbose:
-            print_subprocess_args(self.prefix, *args, **kwargs)
-        if self.quiet:
-            with open(os.devnull, 'w') as devnull:
-                return subprocess.check_call(*args, stdout=devnull, **kwargs)
-        else:
-            return subprocess.check_call(*args, **kwargs)
-
-    def call(self, *args, **kwargs):
-        """Wrapper for subprocess.check().
-
-        Args:
-            *args: to be passed to subprocess.check_call()
-            **kwargs: to be passed to subprocess.check_call()
-        Returns:
-            Whatever subprocess.call() returns.
-        Raises:
-            OSError or subprocess.CalledProcessError: raised by call.
-        """
-        if self.verbose:
-            print_subprocess_args(self.prefix, *args, **kwargs)
-        if self.quiet:
-            with open(os.devnull, 'w') as devnull:
-                return subprocess.call(*args, stdout=devnull, **kwargs)
-        else:
-            return subprocess.call(*args, **kwargs)
-
-    def check_output(self, *args, **kwargs):
-        """Wrapper for subprocess.check_output().
-
-        Args:
-            *args: to be passed to subprocess.check_output()
-            **kwargs: to be passed to subprocess.check_output()
-        Returns:
-            Whatever subprocess.check_output() returns.
-        Raises:
-            OSError or subprocess.CalledProcessError: raised by check_output.
-        """
-        if self.verbose:
-            print_subprocess_args(self.prefix, *args, **kwargs)
-        return subprocess.check_output(*args, **kwargs)
-
-    def strip_output(self, *args, **kwargs):
-        """Wrap subprocess.check_output and str.strip().
-
-        Pass the given arguments into subprocess.check_output() and return
-        the results, after stripping any excess whitespace.
-
-        Args:
-            *args: to be passed to subprocess.check_output()
-            **kwargs: to be passed to subprocess.check_output()
-
-        Returns:
-            The output of the process as a string without leading or
-            trailing whitespace.
-        Raises:
-            OSError or subprocess.CalledProcessError: raised by check_output.
-        """
-        if self.verbose:
-            print_subprocess_args(self.prefix, *args, **kwargs)
-        return str(subprocess.check_output(*args, **kwargs)).strip()
-
-    def popen(self, *args, **kwargs):
-        """Wrapper for subprocess.Popen().
-
-        Args:
-            *args: to be passed to subprocess.Popen()
-            **kwargs: to be passed to subprocess.Popen()
-        Returns:
-            The output of subprocess.Popen()
-        Raises:
-            OSError or subprocess.CalledProcessError: raised by Popen.
-        """
-        if self.verbose:
-            print_subprocess_args(self.prefix, *args, **kwargs)
-        return subprocess.Popen(*args, **kwargs)
-
-
-class ChangeDir(object):
-    """Use with a with-statement to temporarily change directories."""
-    # pylint: disable=I0011,R0903
-
-    def __init__(self, directory, verbose=False):
-        self._directory = directory
-        self._verbose = verbose
-
-    def __enter__(self):
-        if self._directory != os.curdir:
-            if self._verbose:
-                print '~~$ cd %s' % self._directory
-            cwd = os.getcwd()
-            os.chdir(self._directory)
-            self._directory = cwd
-
-    def __exit__(self, etype, value, traceback):
-        if self._directory != os.curdir:
-            if self._verbose:
-                print '~~$ cd %s' % self._directory
-            os.chdir(self._directory)
+import re
 
 
 class ReSearch(object):
     """A collection of static methods for regexing things."""
 
     @staticmethod
     def search_within_stream(input_stream, pattern, default=None):
         """Search for regular expression in a file-like object.
 
         Opens a file for reading and searches line by line for a match to
@@ skipping 28 matching lines @@
         Args:
             input_string: (string) to be searched
             pattern: (string) to be passed to re.compile
             default: what to return if no match
 
         Returns:
             A string or whatever default is
         """
         match = re.search(pattern, input_string)
         return match.group('return') if match else default
-
-    @staticmethod
-    def search_within_output(verbose, pattern, default, *args, **kwargs):
-        """Search for regular expression in a process output.
-
-        Does not search across newlines.
-
-        Args:
-            verbose: (boolean) shoule we call print_subprocess_args?
-            pattern: (string) to be passed to re.compile
-            default: what to return if no match
-            *args: to be passed to subprocess.Popen()
-            **kwargs: to be passed to subprocess.Popen()
-
-        Returns:
-            A string or whatever default is
-        """
-        if verbose:
-            print_subprocess_args('~~$ ', *args, **kwargs)
-        proc = subprocess.Popen(*args, stdout=subprocess.PIPE, **kwargs)
-        return ReSearch.search_within_stream(proc.stdout, pattern, default)
-
-