stgit/utils.py

   1 """Common utility functions
   2 """
   3
   4 import errno, os, os.path, sys
   5 from stgit.config import config
   6
   7 __copyright__ = """
   8 Copyright (C) 2005, Catalin Marinas <catalin.marinas@gmail.com>
   9
  10 This program is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License version 2 as
  12 published by the Free Software Foundation.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this program; if not, write to the Free Software
  21 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22 """
  23
  24 def mkdir_file(filename, mode):
  25     """Opens filename with the given mode, creating the directory it's
  26     in if it doesn't already exist."""
  27     create_dirs(os.path.dirname(filename))
  28     return file(filename, mode)
  29
  30 def read_string(filename, multiline = False):
  31     """Reads the first line from a file
  32     """
  33     f = file(filename, 'r')
  34     if multiline:
  35         result = f.read()
  36     else:
  37         result = f.readline().strip()
  38     f.close()
  39     return result
  40
  41 def write_string(filename, line, multiline = False):
  42     """Writes 'line' to file and truncates it
  43     """
  44     f = mkdir_file(filename, 'w+')
  45     if multiline:
  46         f.write(line)
  47     else:
  48         print >> f, line
  49     f.close()
  50
  51 def append_strings(filename, lines):
  52     """Appends 'lines' sequence to file
  53     """
  54     f = mkdir_file(filename, 'a+')
  55     for line in lines:
  56         print >> f, line
  57     f.close()
  58
  59 def append_string(filename, line):
  60     """Appends 'line' to file
  61     """
  62     f = mkdir_file(filename, 'a+')
  63     print >> f, line
  64     f.close()
  65
  66 def insert_string(filename, line):
  67     """Inserts 'line' at the beginning of the file
  68     """
  69     f = mkdir_file(filename, 'r+')
  70     lines = f.readlines()
  71     f.seek(0); f.truncate()
  72     print >> f, line
  73     f.writelines(lines)
  74     f.close()
  75
  76 def create_empty_file(name):
  77     """Creates an empty file
  78     """
  79     mkdir_file(name, 'w+').close()
  80
  81 def list_files_and_dirs(path):
  82     """Return the sets of filenames and directory names in a
  83     directory."""
  84     files, dirs = [], []
  85     for fd in os.listdir(path):
  86         full_fd = os.path.join(path, fd)
  87         if os.path.isfile(full_fd):
  88             files.append(fd)
  89         elif os.path.isdir(full_fd):
  90             dirs.append(fd)
  91     return files, dirs
  92
  93 def walk_tree(basedir):
  94     """Starting in the given directory, iterate through all its
  95     subdirectories. For each subdirectory, yield the name of the
  96     subdirectory (relative to the base directory), the list of
  97     filenames in the subdirectory, and the list of directory names in
  98     the subdirectory."""
  99     subdirs = ['']
 100     while subdirs:
 101         subdir = subdirs.pop()
 102         files, dirs = list_files_and_dirs(os.path.join(basedir, subdir))
 103         for d in dirs:
 104             subdirs.append(os.path.join(subdir, d))
 105         yield subdir, files, dirs
 106
 107 def strip_prefix(prefix, string):
 108     """Return string, without the prefix. Blow up if string doesn't
 109     start with prefix."""
 110     assert string.startswith(prefix)
 111     return string[len(prefix):]
 112
 113 def strip_suffix(suffix, string):
 114     """Return string, without the suffix. Blow up if string doesn't
 115     end with suffix."""
 116     assert string.endswith(suffix)
 117     return string[:-len(suffix)]
 118
 119 def remove_dirs(basedir, dirs):
 120     """Starting at join(basedir, dirs), remove the directory if empty,
 121     and try the same with its parent, until we find a nonempty
 122     directory or reach basedir."""
 123     path = dirs
 124     while path:
 125         try:
 126             os.rmdir(os.path.join(basedir, path))
 127         except OSError:
 128             return # can't remove nonempty directory
 129         path = os.path.dirname(path)
 130
 131 def remove_file_and_dirs(basedir, file):
 132     """Remove join(basedir, file), and then remove the directory it
 133     was in if empty, and try the same with its parent, until we find a
 134     nonempty directory or reach basedir."""
 135     os.remove(os.path.join(basedir, file))
 136     remove_dirs(basedir, os.path.dirname(file))
 137
 138 def create_dirs(directory):
 139     """Create the given directory, if the path doesn't already exist."""
 140     if directory and not os.path.isdir(directory):
 141         create_dirs(os.path.dirname(directory))
 142         try:
 143             os.mkdir(directory)
 144         except OSError, e:
 145             if e.errno != errno.EEXIST:
 146                 raise e
 147
 148 def rename(basedir, file1, file2):
 149     """Rename join(basedir, file1) to join(basedir, file2), not
 150     leaving any empty directories behind and creating any directories
 151     necessary."""
 152     full_file2 = os.path.join(basedir, file2)
 153     create_dirs(os.path.dirname(full_file2))
 154     os.rename(os.path.join(basedir, file1), full_file2)
 155     remove_dirs(basedir, os.path.dirname(file1))
 156
 157 class EditorException(Exception):
 158     pass
 159
 160 def call_editor(filename):
 161     """Run the editor on the specified filename."""
 162
 163     # the editor
 164     editor = config.get('stgit.editor')
 165     if editor:
 166         pass
 167     elif 'EDITOR' in os.environ:
 168         editor = os.environ['EDITOR']
 169     else:
 170         editor = 'vi'
 171     editor += ' %s' % filename
 172
 173     print 'Invoking the editor: "%s"...' % editor,
 174     sys.stdout.flush()
 175     err = os.system(editor)
 176     if err:
 177         raise EditorException, 'editor failed, exit code: %d' % err
 178     print 'done'