1 | """Utilities for comparing files and directories. |
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2 | |
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3 | Classes: |
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4 | dircmp |
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5 | |
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6 | Functions: |
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7 | cmp(f1, f2, shallow=1) -> int |
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8 | cmpfiles(a, b, common) -> ([], [], []) |
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9 | |
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10 | """ |
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11 | |
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12 | import os |
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13 | import stat |
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14 | from itertools import ifilter, ifilterfalse, imap, izip |
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15 | |
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16 | __all__ = ["cmp","dircmp","cmpfiles"] |
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17 | |
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18 | _cache = {} |
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19 | BUFSIZE=8*1024 |
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20 | |
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21 | def cmp(f1, f2, shallow=1): |
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22 | """Compare two files. |
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23 | |
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24 | Arguments: |
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25 | |
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26 | f1 -- First file name |
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27 | |
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28 | f2 -- Second file name |
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29 | |
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30 | shallow -- Just check stat signature (do not read the files). |
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31 | defaults to 1. |
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32 | |
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33 | Return value: |
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34 | |
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35 | True if the files are the same, False otherwise. |
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36 | |
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37 | This function uses a cache for past comparisons and the results, |
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38 | with a cache invalidation mechanism relying on stale signatures. |
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39 | |
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40 | """ |
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41 | |
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42 | s1 = _sig(os.stat(f1)) |
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43 | s2 = _sig(os.stat(f2)) |
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44 | if s1[0] != stat.S_IFREG or s2[0] != stat.S_IFREG: |
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45 | return False |
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46 | if shallow and s1 == s2: |
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47 | return True |
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48 | if s1[1] != s2[1]: |
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49 | return False |
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50 | |
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51 | outcome = _cache.get((f1, f2, s1, s2)) |
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52 | if outcome is None: |
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53 | outcome = _do_cmp(f1, f2) |
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54 | if len(_cache) > 100: # limit the maximum size of the cache |
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55 | _cache.clear() |
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56 | _cache[f1, f2, s1, s2] = outcome |
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57 | return outcome |
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58 | |
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59 | def _sig(st): |
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60 | return (stat.S_IFMT(st.st_mode), |
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61 | st.st_size, |
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62 | st.st_mtime) |
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63 | |
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64 | def _do_cmp(f1, f2): |
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65 | bufsize = BUFSIZE |
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66 | with open(f1, 'rb') as fp1, open(f2, 'rb') as fp2: |
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67 | while True: |
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68 | b1 = fp1.read(bufsize) |
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69 | b2 = fp2.read(bufsize) |
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70 | if b1 != b2: |
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71 | return False |
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72 | if not b1: |
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73 | return True |
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74 | |
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75 | # Directory comparison class. |
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76 | # |
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77 | class dircmp: |
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78 | """A class that manages the comparison of 2 directories. |
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79 | |
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80 | dircmp(a,b,ignore=None,hide=None) |
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81 | A and B are directories. |
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82 | IGNORE is a list of names to ignore, |
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83 | defaults to ['RCS', 'CVS', 'tags']. |
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84 | HIDE is a list of names to hide, |
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85 | defaults to [os.curdir, os.pardir]. |
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86 | |
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87 | High level usage: |
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88 | x = dircmp(dir1, dir2) |
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89 | x.report() -> prints a report on the differences between dir1 and dir2 |
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90 | or |
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91 | x.report_partial_closure() -> prints report on differences between dir1 |
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92 | and dir2, and reports on common immediate subdirectories. |
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93 | x.report_full_closure() -> like report_partial_closure, |
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94 | but fully recursive. |
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95 | |
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96 | Attributes: |
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97 | left_list, right_list: The files in dir1 and dir2, |
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98 | filtered by hide and ignore. |
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99 | common: a list of names in both dir1 and dir2. |
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100 | left_only, right_only: names only in dir1, dir2. |
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101 | common_dirs: subdirectories in both dir1 and dir2. |
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102 | common_files: files in both dir1 and dir2. |
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103 | common_funny: names in both dir1 and dir2 where the type differs between |
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104 | dir1 and dir2, or the name is not stat-able. |
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105 | same_files: list of identical files. |
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106 | diff_files: list of filenames which differ. |
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107 | funny_files: list of files which could not be compared. |
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108 | subdirs: a dictionary of dircmp objects, keyed by names in common_dirs. |
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109 | """ |
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110 | |
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111 | def __init__(self, a, b, ignore=None, hide=None): # Initialize |
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112 | self.left = a |
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113 | self.right = b |
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114 | if hide is None: |
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115 | self.hide = [os.curdir, os.pardir] # Names never to be shown |
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116 | else: |
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117 | self.hide = hide |
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118 | if ignore is None: |
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119 | self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison |
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120 | else: |
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121 | self.ignore = ignore |
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122 | |
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123 | def phase0(self): # Compare everything except common subdirectories |
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124 | self.left_list = _filter(os.listdir(self.left), |
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125 | self.hide+self.ignore) |
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126 | self.right_list = _filter(os.listdir(self.right), |
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127 | self.hide+self.ignore) |
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128 | self.left_list.sort() |
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129 | self.right_list.sort() |
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130 | |
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131 | def phase1(self): # Compute common names |
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132 | a = dict(izip(imap(os.path.normcase, self.left_list), self.left_list)) |
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133 | b = dict(izip(imap(os.path.normcase, self.right_list), self.right_list)) |
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134 | self.common = map(a.__getitem__, ifilter(b.__contains__, a)) |
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135 | self.left_only = map(a.__getitem__, ifilterfalse(b.__contains__, a)) |
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136 | self.right_only = map(b.__getitem__, ifilterfalse(a.__contains__, b)) |
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137 | |
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138 | def phase2(self): # Distinguish files, directories, funnies |
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139 | self.common_dirs = [] |
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140 | self.common_files = [] |
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141 | self.common_funny = [] |
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142 | |
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143 | for x in self.common: |
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144 | a_path = os.path.join(self.left, x) |
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145 | b_path = os.path.join(self.right, x) |
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146 | |
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147 | ok = 1 |
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148 | try: |
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149 | a_stat = os.stat(a_path) |
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150 | except os.error, why: |
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151 | # print 'Can\'t stat', a_path, ':', why[1] |
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152 | ok = 0 |
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153 | try: |
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154 | b_stat = os.stat(b_path) |
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155 | except os.error, why: |
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156 | # print 'Can\'t stat', b_path, ':', why[1] |
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157 | ok = 0 |
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158 | |
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159 | if ok: |
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160 | a_type = stat.S_IFMT(a_stat.st_mode) |
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161 | b_type = stat.S_IFMT(b_stat.st_mode) |
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162 | if a_type != b_type: |
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163 | self.common_funny.append(x) |
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164 | elif stat.S_ISDIR(a_type): |
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165 | self.common_dirs.append(x) |
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166 | elif stat.S_ISREG(a_type): |
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167 | self.common_files.append(x) |
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168 | else: |
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169 | self.common_funny.append(x) |
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170 | else: |
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171 | self.common_funny.append(x) |
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172 | |
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173 | def phase3(self): # Find out differences between common files |
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174 | xx = cmpfiles(self.left, self.right, self.common_files) |
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175 | self.same_files, self.diff_files, self.funny_files = xx |
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176 | |
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177 | def phase4(self): # Find out differences between common subdirectories |
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178 | # A new dircmp object is created for each common subdirectory, |
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179 | # these are stored in a dictionary indexed by filename. |
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180 | # The hide and ignore properties are inherited from the parent |
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181 | self.subdirs = {} |
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182 | for x in self.common_dirs: |
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183 | a_x = os.path.join(self.left, x) |
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184 | b_x = os.path.join(self.right, x) |
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185 | self.subdirs[x] = dircmp(a_x, b_x, self.ignore, self.hide) |
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186 | |
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187 | def phase4_closure(self): # Recursively call phase4() on subdirectories |
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188 | self.phase4() |
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189 | for sd in self.subdirs.itervalues(): |
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190 | sd.phase4_closure() |
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191 | |
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192 | def report(self): # Print a report on the differences between a and b |
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193 | # Output format is purposely lousy |
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194 | print 'diff', self.left, self.right |
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195 | if self.left_only: |
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196 | self.left_only.sort() |
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197 | print 'Only in', self.left, ':', self.left_only |
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198 | if self.right_only: |
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199 | self.right_only.sort() |
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200 | print 'Only in', self.right, ':', self.right_only |
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201 | if self.same_files: |
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202 | self.same_files.sort() |
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203 | print 'Identical files :', self.same_files |
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204 | if self.diff_files: |
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205 | self.diff_files.sort() |
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206 | print 'Differing files :', self.diff_files |
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207 | if self.funny_files: |
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208 | self.funny_files.sort() |
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209 | print 'Trouble with common files :', self.funny_files |
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210 | if self.common_dirs: |
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211 | self.common_dirs.sort() |
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212 | print 'Common subdirectories :', self.common_dirs |
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213 | if self.common_funny: |
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214 | self.common_funny.sort() |
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215 | print 'Common funny cases :', self.common_funny |
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216 | |
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217 | def report_partial_closure(self): # Print reports on self and on subdirs |
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218 | self.report() |
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219 | for sd in self.subdirs.itervalues(): |
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220 | print |
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221 | sd.report() |
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222 | |
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223 | def report_full_closure(self): # Report on self and subdirs recursively |
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224 | self.report() |
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225 | for sd in self.subdirs.itervalues(): |
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226 | print |
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227 | sd.report_full_closure() |
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228 | |
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229 | methodmap = dict(subdirs=phase4, |
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230 | same_files=phase3, diff_files=phase3, funny_files=phase3, |
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231 | common_dirs = phase2, common_files=phase2, common_funny=phase2, |
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232 | common=phase1, left_only=phase1, right_only=phase1, |
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233 | left_list=phase0, right_list=phase0) |
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234 | |
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235 | def __getattr__(self, attr): |
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236 | if attr not in self.methodmap: |
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237 | raise AttributeError, attr |
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238 | self.methodmap[attr](self) |
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239 | return getattr(self, attr) |
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240 | |
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241 | def cmpfiles(a, b, common, shallow=1): |
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242 | """Compare common files in two directories. |
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243 | |
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244 | a, b -- directory names |
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245 | common -- list of file names found in both directories |
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246 | shallow -- if true, do comparison based solely on stat() information |
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247 | |
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248 | Returns a tuple of three lists: |
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249 | files that compare equal |
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250 | files that are different |
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251 | filenames that aren't regular files. |
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252 | |
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253 | """ |
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254 | res = ([], [], []) |
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255 | for x in common: |
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256 | ax = os.path.join(a, x) |
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257 | bx = os.path.join(b, x) |
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258 | res[_cmp(ax, bx, shallow)].append(x) |
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259 | return res |
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260 | |
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261 | |
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262 | # Compare two files. |
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263 | # Return: |
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264 | # 0 for equal |
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265 | # 1 for different |
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266 | # 2 for funny cases (can't stat, etc.) |
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267 | # |
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268 | def _cmp(a, b, sh, abs=abs, cmp=cmp): |
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269 | try: |
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270 | return not abs(cmp(a, b, sh)) |
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271 | except (os.error, IOError): |
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272 | return 2 |
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273 | |
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274 | |
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275 | # Return a copy with items that occur in skip removed. |
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276 | # |
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277 | def _filter(flist, skip): |
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278 | return list(ifilterfalse(skip.__contains__, flist)) |
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279 | |
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280 | |
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281 | # Demonstration and testing. |
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282 | # |
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283 | def demo(): |
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284 | import sys |
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285 | import getopt |
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286 | options, args = getopt.getopt(sys.argv[1:], 'r') |
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287 | if len(args) != 2: |
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288 | raise getopt.GetoptError('need exactly two args', None) |
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289 | dd = dircmp(args[0], args[1]) |
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290 | if ('-r', '') in options: |
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291 | dd.report_full_closure() |
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292 | else: |
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293 | dd.report() |
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294 | |
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295 | if __name__ == '__main__': |
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296 | demo() |
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