| 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 remove_dirs(basedir, dirs): |
| 113 | """Starting at join(basedir, dirs), remove the directory if empty, |
| 114 | and try the same with its parent, until we find a nonempty |
| 115 | directory or reach basedir.""" |
| 116 | path = dirs |
| 117 | while path: |
| 118 | try: |
| 119 | os.rmdir(os.path.join(basedir, path)) |
| 120 | except OSError: |
| 121 | return # can't remove nonempty directory |
| 122 | path = os.path.dirname(path) |
| 123 | |
| 124 | def remove_file_and_dirs(basedir, file): |
| 125 | """Remove join(basedir, file), and then remove the directory it |
| 126 | was in if empty, and try the same with its parent, until we find a |
| 127 | nonempty directory or reach basedir.""" |
| 128 | os.remove(os.path.join(basedir, file)) |
| 129 | remove_dirs(basedir, os.path.dirname(file)) |
| 130 | |
| 131 | def create_dirs(directory): |
| 132 | """Create the given directory, if the path doesn't already exist.""" |
| 133 | if directory and not os.path.isdir(directory): |
| 134 | create_dirs(os.path.dirname(directory)) |
| 135 | try: |
| 136 | os.mkdir(directory) |
| 137 | except OSError, e: |
| 138 | if e.errno != errno.EEXIST: |
| 139 | raise e |
| 140 | |
| 141 | def rename(basedir, file1, file2): |
| 142 | """Rename join(basedir, file1) to join(basedir, file2), not |
| 143 | leaving any empty directories behind and creating any directories |
| 144 | necessary.""" |
| 145 | full_file2 = os.path.join(basedir, file2) |
| 146 | create_dirs(os.path.dirname(full_file2)) |
| 147 | os.rename(os.path.join(basedir, file1), full_file2) |
| 148 | remove_dirs(basedir, os.path.dirname(file1)) |