mdw@git.distorted.org.uk Git - stgit/blob - stgit/utils.py

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