1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * Mini diff implementation for busybox, adapted from OpenBSD diff.
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4 | *
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5 | * Copyright (C) 2010 by Matheus Izvekov <mizvekov@gmail.com>
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6 | * Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
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7 | * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
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8 | *
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9 | * Sponsored in part by the Defense Advanced Research Projects
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10 | * Agency (DARPA) and Air Force Research Laboratory, Air Force
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11 | * Materiel Command, USAF, under agreement number F39502-99-1-0512.
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12 | *
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13 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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14 | */
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15 |
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16 | /*
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17 | * The following code uses an algorithm due to Harold Stone,
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18 | * which finds a pair of longest identical subsequences in
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19 | * the two files.
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20 | *
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21 | * The major goal is to generate the match vector J.
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22 | * J[i] is the index of the line in file1 corresponding
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23 | * to line i in file0. J[i] = 0 if there is no
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24 | * such line in file1.
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25 | *
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26 | * Lines are hashed so as to work in core. All potential
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27 | * matches are located by sorting the lines of each file
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28 | * on the hash (called "value"). In particular, this
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29 | * collects the equivalence classes in file1 together.
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30 | * Subroutine equiv replaces the value of each line in
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31 | * file0 by the index of the first element of its
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32 | * matching equivalence in (the reordered) file1.
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33 | * To save space equiv squeezes file1 into a single
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34 | * array member in which the equivalence classes
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35 | * are simply concatenated, except that their first
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36 | * members are flagged by changing sign.
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37 | *
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38 | * Next the indices that point into member are unsorted into
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39 | * array class according to the original order of file0.
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40 | *
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41 | * The cleverness lies in routine stone. This marches
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42 | * through the lines of file0, developing a vector klist
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43 | * of "k-candidates". At step i a k-candidate is a matched
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44 | * pair of lines x,y (x in file0, y in file1) such that
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45 | * there is a common subsequence of length k
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46 | * between the first i lines of file0 and the first y
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47 | * lines of file1, but there is no such subsequence for
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48 | * any smaller y. x is the earliest possible mate to y
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49 | * that occurs in such a subsequence.
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50 | *
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51 | * Whenever any of the members of the equivalence class of
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52 | * lines in file1 matable to a line in file0 has serial number
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53 | * less than the y of some k-candidate, that k-candidate
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54 | * with the smallest such y is replaced. The new
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55 | * k-candidate is chained (via pred) to the current
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56 | * k-1 candidate so that the actual subsequence can
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57 | * be recovered. When a member has serial number greater
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58 | * that the y of all k-candidates, the klist is extended.
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59 | * At the end, the longest subsequence is pulled out
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60 | * and placed in the array J by unravel
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61 | *
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62 | * With J in hand, the matches there recorded are
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63 | * checked against reality to assure that no spurious
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64 | * matches have crept in due to hashing. If they have,
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65 | * they are broken, and "jackpot" is recorded--a harmless
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66 | * matter except that a true match for a spuriously
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67 | * mated line may now be unnecessarily reported as a change.
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68 | *
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69 | * Much of the complexity of the program comes simply
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70 | * from trying to minimize core utilization and
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71 | * maximize the range of doable problems by dynamically
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72 | * allocating what is needed and reusing what is not.
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73 | * The core requirements for problems larger than somewhat
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74 | * are (in words) 2*length(file0) + length(file1) +
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75 | * 3*(number of k-candidates installed), typically about
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76 | * 6n words for files of length n.
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77 | */
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78 |
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79 | //usage:#define diff_trivial_usage
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80 | //usage: "[-abBdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] FILE1 FILE2"
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81 | //usage:#define diff_full_usage "\n\n"
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82 | //usage: "Compare files line by line and output the differences between them.\n"
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83 | //usage: "This implementation supports unified diffs only.\n"
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84 | //usage: "\n -a Treat all files as text"
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85 | //usage: "\n -b Ignore changes in the amount of whitespace"
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86 | //usage: "\n -B Ignore changes whose lines are all blank"
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87 | //usage: "\n -d Try hard to find a smaller set of changes"
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88 | //usage: "\n -i Ignore case differences"
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89 | //usage: "\n -L Use LABEL instead of the filename in the unified header"
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90 | //usage: "\n -N Treat absent files as empty"
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91 | //usage: "\n -q Output only whether files differ"
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92 | //usage: "\n -r Recurse"
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93 | //usage: "\n -S Start with FILE when comparing directories"
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94 | //usage: "\n -T Make tabs line up by prefixing a tab when necessary"
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95 | //usage: "\n -s Report when two files are the same"
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96 | //usage: "\n -t Expand tabs to spaces in output"
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97 | //usage: "\n -U Output LINES lines of context"
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98 | //usage: "\n -w Ignore all whitespace"
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99 |
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100 | #include "libbb.h"
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101 |
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102 | #if 0
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103 | # define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
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104 | #else
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105 | # define dbg_error_msg(...) ((void)0)
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106 | #endif
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107 |
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108 | enum { /* print_status() and diffreg() return values */
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109 | STATUS_SAME, /* files are the same */
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110 | STATUS_DIFFER, /* files differ */
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111 | STATUS_BINARY, /* binary files differ */
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112 | };
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113 |
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114 | enum { /* Commandline flags */
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115 | FLAG_a,
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116 | FLAG_b,
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117 | FLAG_d,
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118 | FLAG_i,
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119 | FLAG_L, /* never used, handled by getopt32 */
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120 | FLAG_N,
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121 | FLAG_q,
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122 | FLAG_r,
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123 | FLAG_s,
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124 | FLAG_S, /* never used, handled by getopt32 */
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125 | FLAG_t,
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126 | FLAG_T,
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127 | FLAG_U, /* never used, handled by getopt32 */
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128 | FLAG_w,
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129 | FLAG_u, /* ignored, this is the default */
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130 | FLAG_p, /* not implemented */
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131 | FLAG_B,
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132 | FLAG_E, /* not implemented */
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133 | };
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134 | #define FLAG(x) (1 << FLAG_##x)
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135 |
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136 | /* We cache file position to avoid excessive seeking */
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137 | typedef struct FILE_and_pos_t {
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138 | FILE *ft_fp;
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139 | off_t ft_pos;
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140 | } FILE_and_pos_t;
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141 |
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142 | struct globals {
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143 | smallint exit_status;
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144 | int opt_U_context;
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145 | const char *other_dir;
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146 | char *label[2];
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147 | struct stat stb[2];
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148 | };
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149 | #define G (*ptr_to_globals)
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150 | #define exit_status (G.exit_status )
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151 | #define opt_U_context (G.opt_U_context )
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152 | #define label (G.label )
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153 | #define stb (G.stb )
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154 | #define INIT_G() do { \
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155 | SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
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156 | opt_U_context = 3; \
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157 | } while (0)
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158 |
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159 | typedef int token_t;
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160 |
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161 | enum {
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162 | /* Public */
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163 | TOK_EMPTY = 1 << 9, /* Line fully processed, you can proceed to the next */
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164 | TOK_EOF = 1 << 10, /* File ended */
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165 | /* Private (Only to be used by read_token() */
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166 | TOK_EOL = 1 << 11, /* we saw EOL (sticky) */
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167 | TOK_SPACE = 1 << 12, /* used -b code, means we are skipping spaces */
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168 | SHIFT_EOF = (sizeof(token_t)*8 - 8) - 1,
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169 | CHAR_MASK = 0x1ff, /* 8th bit is used to distinguish EOF from 0xff */
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170 | };
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171 |
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172 | /* Restores full EOF from one 8th bit: */
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173 | //#define TOK2CHAR(t) (((t) << SHIFT_EOF) >> SHIFT_EOF)
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174 | /* We don't really need the above, we only need to have EOF != any_real_char: */
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175 | #define TOK2CHAR(t) ((t) & CHAR_MASK)
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176 |
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177 | static void seek_ft(FILE_and_pos_t *ft, off_t pos)
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178 | {
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179 | if (ft->ft_pos != pos) {
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180 | ft->ft_pos = pos;
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181 | fseeko(ft->ft_fp, pos, SEEK_SET);
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182 | }
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183 | }
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184 |
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185 | /* Reads tokens from given fp, handling -b and -w flags
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186 | * The user must reset tok every line start
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187 | */
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188 | static int read_token(FILE_and_pos_t *ft, token_t tok)
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189 | {
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190 | tok |= TOK_EMPTY;
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191 | while (!(tok & TOK_EOL)) {
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192 | bool is_space;
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193 | int t;
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194 |
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195 | t = fgetc(ft->ft_fp);
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196 | if (t != EOF)
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197 | ft->ft_pos++;
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198 | is_space = (t == EOF || isspace(t));
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199 |
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200 | /* If t == EOF (-1), set both TOK_EOF and TOK_EOL */
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201 | tok |= (t & (TOK_EOF + TOK_EOL));
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202 | /* Only EOL? */
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203 | if (t == '\n')
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204 | tok |= TOK_EOL;
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205 |
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206 | if (option_mask32 & FLAG(i)) /* Handcoded tolower() */
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207 | t = (t >= 'A' && t <= 'Z') ? t - ('A' - 'a') : t;
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208 |
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209 | if ((option_mask32 & FLAG(w)) && is_space)
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210 | continue;
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211 |
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212 | /* Trim char value to low 9 bits */
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213 | t &= CHAR_MASK;
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214 |
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215 | if (option_mask32 & FLAG(b)) {
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216 | /* Was prev char whitespace? */
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217 | if (tok & TOK_SPACE) { /* yes */
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218 | if (is_space) /* this one too, ignore it */
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219 | continue;
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220 | tok &= ~TOK_SPACE;
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221 | } else if (is_space) {
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222 | /* 1st whitespace char.
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223 | * Set TOK_SPACE and replace char by ' ' */
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224 | t = TOK_SPACE + ' ';
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225 | }
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226 | }
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227 | /* Clear EMPTY */
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228 | tok &= ~(TOK_EMPTY + CHAR_MASK);
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229 | /* Assign char value (low 9 bits) and maybe set TOK_SPACE */
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230 | tok |= t;
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231 | break;
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232 | }
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233 | #if 0
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234 | bb_error_msg("fp:%p tok:%x '%c'%s%s%s%s", fp, tok, tok & 0xff
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235 | , tok & TOK_EOF ? " EOF" : ""
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236 | , tok & TOK_EOL ? " EOL" : ""
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237 | , tok & TOK_EMPTY ? " EMPTY" : ""
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238 | , tok & TOK_SPACE ? " SPACE" : ""
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239 | );
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240 | #endif
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241 | return tok;
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242 | }
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243 |
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244 | struct cand {
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245 | int x;
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246 | int y;
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247 | int pred;
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248 | };
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249 |
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250 | static int search(const int *c, int k, int y, const struct cand *list)
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251 | {
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252 | int i, j;
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253 |
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254 | if (list[c[k]].y < y) /* quick look for typical case */
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255 | return k + 1;
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256 |
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257 | for (i = 0, j = k + 1;;) {
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258 | const int l = (i + j) >> 1;
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259 | if (l > i) {
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260 | const int t = list[c[l]].y;
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261 | if (t > y)
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262 | j = l;
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263 | else if (t < y)
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264 | i = l;
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265 | else
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266 | return l;
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267 | } else
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268 | return l + 1;
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269 | }
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270 | }
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271 |
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272 | static unsigned isqrt(unsigned n)
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273 | {
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274 | unsigned x = 1;
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275 | while (1) {
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276 | const unsigned y = x;
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277 | x = ((n / x) + x) >> 1;
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278 | if (x <= (y + 1) && x >= (y - 1))
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279 | return x;
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280 | }
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281 | }
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282 |
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283 | static void stone(const int *a, int n, const int *b, int *J, int pref)
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284 | {
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285 | const unsigned isq = isqrt(n);
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286 | const unsigned bound =
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287 | (option_mask32 & FLAG(d)) ? UINT_MAX : MAX(256, isq);
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288 | int clen = 1;
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289 | int clistlen = 100;
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290 | int k = 0;
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291 | struct cand *clist = xzalloc(clistlen * sizeof(clist[0]));
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292 | struct cand cand;
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293 | struct cand *q;
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294 | int *klist = xzalloc((n + 2) * sizeof(klist[0]));
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295 | /*clist[0] = (struct cand){0}; - xzalloc did it */
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296 | /*klist[0] = 0; */
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297 |
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298 | for (cand.x = 1; cand.x <= n; cand.x++) {
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299 | int j = a[cand.x], oldl = 0;
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300 | unsigned numtries = 0;
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301 | if (j == 0)
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302 | continue;
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303 | cand.y = -b[j];
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304 | cand.pred = klist[0];
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305 | do {
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306 | int l, tc;
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307 | if (cand.y <= clist[cand.pred].y)
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308 | continue;
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309 | l = search(klist, k, cand.y, clist);
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310 | if (l != oldl + 1)
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311 | cand.pred = klist[l - 1];
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312 | if (l <= k && clist[klist[l]].y <= cand.y)
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313 | continue;
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314 | if (clen == clistlen) {
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315 | clistlen = clistlen * 11 / 10;
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316 | clist = xrealloc(clist, clistlen * sizeof(clist[0]));
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317 | }
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318 | clist[clen] = cand;
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319 | tc = klist[l];
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320 | klist[l] = clen++;
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321 | if (l <= k) {
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322 | cand.pred = tc;
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323 | oldl = l;
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324 | numtries++;
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325 | } else {
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326 | k++;
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327 | break;
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328 | }
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329 | } while ((cand.y = b[++j]) > 0 && numtries < bound);
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330 | }
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331 | /* Unravel */
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332 | for (q = clist + klist[k]; q->y; q = clist + q->pred)
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333 | J[q->x + pref] = q->y + pref;
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334 | free(klist);
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335 | free(clist);
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336 | }
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337 |
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338 | struct line {
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339 | /* 'serial' is not used in the begining, so we reuse it
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340 | * to store line offsets, thus reducing memory pressure
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341 | */
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342 | union {
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343 | unsigned serial;
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344 | off_t offset;
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345 | };
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346 | unsigned value;
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347 | };
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348 |
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349 | static void equiv(struct line *a, int n, struct line *b, int m, int *c)
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350 | {
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351 | int i = 1, j = 1;
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352 |
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353 | while (i <= n && j <= m) {
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354 | if (a[i].value < b[j].value)
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355 | a[i++].value = 0;
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356 | else if (a[i].value == b[j].value)
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357 | a[i++].value = j;
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358 | else
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359 | j++;
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360 | }
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361 | while (i <= n)
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362 | a[i++].value = 0;
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363 | b[m + 1].value = 0;
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364 | j = 0;
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365 | while (++j <= m) {
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366 | c[j] = -b[j].serial;
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367 | while (b[j + 1].value == b[j].value) {
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368 | j++;
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369 | c[j] = b[j].serial;
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370 | }
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371 | }
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372 | c[j] = -1;
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373 | }
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374 |
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375 | static void unsort(const struct line *f, int l, int *b)
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376 | {
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377 | int i;
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378 | int *a = xmalloc((l + 1) * sizeof(a[0]));
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379 | for (i = 1; i <= l; i++)
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380 | a[f[i].serial] = f[i].value;
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381 | for (i = 1; i <= l; i++)
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382 | b[i] = a[i];
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383 | free(a);
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384 | }
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385 |
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386 | static int line_compar(const void *a, const void *b)
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387 | {
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388 | #define l0 ((const struct line*)a)
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389 | #define l1 ((const struct line*)b)
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390 | int r = l0->value - l1->value;
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391 | if (r)
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392 | return r;
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393 | return l0->serial - l1->serial;
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394 | #undef l0
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395 | #undef l1
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396 | }
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397 |
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398 | static void fetch(FILE_and_pos_t *ft, const off_t *ix, int a, int b, int ch)
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399 | {
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400 | int i, j, col;
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401 | for (i = a; i <= b; i++) {
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402 | seek_ft(ft, ix[i - 1]);
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403 | putchar(ch);
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404 | if (option_mask32 & FLAG(T))
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405 | putchar('\t');
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406 | for (j = 0, col = 0; j < ix[i] - ix[i - 1]; j++) {
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407 | int c = fgetc(ft->ft_fp);
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408 | if (c == EOF) {
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409 | printf("\n\\ No newline at end of file\n");
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410 | return;
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411 | }
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412 | ft->ft_pos++;
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413 | if (c == '\t' && (option_mask32 & FLAG(t)))
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414 | do putchar(' '); while (++col & 7);
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415 | else {
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416 | putchar(c);
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417 | col++;
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418 | }
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419 | }
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420 | }
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421 | }
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422 |
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423 | /* Creates the match vector J, where J[i] is the index
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424 | * of the line in the new file corresponding to the line i
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425 | * in the old file. Lines start at 1 instead of 0, that value
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426 | * being used instead to denote no corresponding line.
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427 | * This vector is dynamically allocated and must be freed by the caller.
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428 | *
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429 | * * fp is an input parameter, where fp[0] and fp[1] are the open
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430 | * old file and new file respectively.
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431 | * * nlen is an output variable, where nlen[0] and nlen[1]
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432 | * gets the number of lines in the old and new file respectively.
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433 | * * ix is an output variable, where ix[0] and ix[1] gets
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434 | * assigned dynamically allocated vectors of the offsets of the lines
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435 | * of the old and new file respectively. These must be freed by the caller.
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436 | */
|
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437 | static NOINLINE int *create_J(FILE_and_pos_t ft[2], int nlen[2], off_t *ix[2])
|
---|
438 | {
|
---|
439 | int *J, slen[2], *class, *member;
|
---|
440 | struct line *nfile[2], *sfile[2];
|
---|
441 | int pref = 0, suff = 0, i, j, delta;
|
---|
442 |
|
---|
443 | /* Lines of both files are hashed, and in the process
|
---|
444 | * their offsets are stored in the array ix[fileno]
|
---|
445 | * where fileno == 0 points to the old file, and
|
---|
446 | * fileno == 1 points to the new one.
|
---|
447 | */
|
---|
448 | for (i = 0; i < 2; i++) {
|
---|
449 | unsigned hash;
|
---|
450 | token_t tok;
|
---|
451 | size_t sz = 100;
|
---|
452 | nfile[i] = xmalloc((sz + 3) * sizeof(nfile[i][0]));
|
---|
453 | /* ft gets here without the correct position, cant use seek_ft */
|
---|
454 | ft[i].ft_pos = 0;
|
---|
455 | fseeko(ft[i].ft_fp, 0, SEEK_SET);
|
---|
456 |
|
---|
457 | nlen[i] = 0;
|
---|
458 | /* We could zalloc nfile, but then zalloc starts showing in gprof at ~1% */
|
---|
459 | nfile[i][0].offset = 0;
|
---|
460 | goto start; /* saves code */
|
---|
461 | while (1) {
|
---|
462 | tok = read_token(&ft[i], tok);
|
---|
463 | if (!(tok & TOK_EMPTY)) {
|
---|
464 | /* Hash algorithm taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578. */
|
---|
465 | /*hash = hash * 128 - hash + TOK2CHAR(tok);
|
---|
466 | * gcc insists on optimizing above to "hash * 127 + ...", thus... */
|
---|
467 | unsigned o = hash - TOK2CHAR(tok);
|
---|
468 | hash = hash * 128 - o; /* we want SPEED here */
|
---|
469 | continue;
|
---|
470 | }
|
---|
471 | if (nlen[i]++ == sz) {
|
---|
472 | sz = sz * 3 / 2;
|
---|
473 | nfile[i] = xrealloc(nfile[i], (sz + 3) * sizeof(nfile[i][0]));
|
---|
474 | }
|
---|
475 | /* line_compar needs hashes fit into positive int */
|
---|
476 | nfile[i][nlen[i]].value = hash & INT_MAX;
|
---|
477 | /* like ftello(ft[i].ft_fp) but faster (avoids lseek syscall) */
|
---|
478 | nfile[i][nlen[i]].offset = ft[i].ft_pos;
|
---|
479 | if (tok & TOK_EOF) {
|
---|
480 | /* EOF counts as a token, so we have to adjust it here */
|
---|
481 | nfile[i][nlen[i]].offset++;
|
---|
482 | break;
|
---|
483 | }
|
---|
484 | start:
|
---|
485 | hash = tok = 0;
|
---|
486 | }
|
---|
487 | /* Exclude lone EOF line from the end of the file, to make fetch()'s job easier */
|
---|
488 | if (nfile[i][nlen[i]].offset - nfile[i][nlen[i] - 1].offset == 1)
|
---|
489 | nlen[i]--;
|
---|
490 | /* Now we copy the line offsets into ix */
|
---|
491 | ix[i] = xmalloc((nlen[i] + 2) * sizeof(ix[i][0]));
|
---|
492 | for (j = 0; j < nlen[i] + 1; j++)
|
---|
493 | ix[i][j] = nfile[i][j].offset;
|
---|
494 | }
|
---|
495 |
|
---|
496 | /* length of prefix and suffix is calculated */
|
---|
497 | for (; pref < nlen[0] && pref < nlen[1] &&
|
---|
498 | nfile[0][pref + 1].value == nfile[1][pref + 1].value;
|
---|
499 | pref++);
|
---|
500 | for (; suff < nlen[0] - pref && suff < nlen[1] - pref &&
|
---|
501 | nfile[0][nlen[0] - suff].value == nfile[1][nlen[1] - suff].value;
|
---|
502 | suff++);
|
---|
503 | /* Arrays are pruned by the suffix and prefix length,
|
---|
504 | * the result being sorted and stored in sfile[fileno],
|
---|
505 | * and their sizes are stored in slen[fileno]
|
---|
506 | */
|
---|
507 | for (j = 0; j < 2; j++) {
|
---|
508 | sfile[j] = nfile[j] + pref;
|
---|
509 | slen[j] = nlen[j] - pref - suff;
|
---|
510 | for (i = 0; i <= slen[j]; i++)
|
---|
511 | sfile[j][i].serial = i;
|
---|
512 | qsort(sfile[j] + 1, slen[j], sizeof(*sfile[j]), line_compar);
|
---|
513 | }
|
---|
514 | /* nfile arrays are reused to reduce memory pressure
|
---|
515 | * The #if zeroed out section performs the same task as the
|
---|
516 | * one in the #else section.
|
---|
517 | * Peak memory usage is higher, but one array copy is avoided
|
---|
518 | * by not using unsort()
|
---|
519 | */
|
---|
520 | #if 0
|
---|
521 | member = xmalloc((slen[1] + 2) * sizeof(member[0]));
|
---|
522 | equiv(sfile[0], slen[0], sfile[1], slen[1], member);
|
---|
523 | free(nfile[1]);
|
---|
524 |
|
---|
525 | class = xmalloc((slen[0] + 1) * sizeof(class[0]));
|
---|
526 | for (i = 1; i <= slen[0]; i++) /* Unsorting */
|
---|
527 | class[sfile[0][i].serial] = sfile[0][i].value;
|
---|
528 | free(nfile[0]);
|
---|
529 | #else
|
---|
530 | member = (int *)nfile[1];
|
---|
531 | equiv(sfile[0], slen[0], sfile[1], slen[1], member);
|
---|
532 | member = xrealloc(member, (slen[1] + 2) * sizeof(member[0]));
|
---|
533 |
|
---|
534 | class = (int *)nfile[0];
|
---|
535 | unsort(sfile[0], slen[0], (int *)nfile[0]);
|
---|
536 | class = xrealloc(class, (slen[0] + 2) * sizeof(class[0]));
|
---|
537 | #endif
|
---|
538 | J = xmalloc((nlen[0] + 2) * sizeof(J[0]));
|
---|
539 | /* The elements of J which fall inside the prefix and suffix regions
|
---|
540 | * are marked as unchanged, while the ones which fall outside
|
---|
541 | * are initialized with 0 (no matches), so that function stone can
|
---|
542 | * then assign them their right values
|
---|
543 | */
|
---|
544 | for (i = 0, delta = nlen[1] - nlen[0]; i <= nlen[0]; i++)
|
---|
545 | J[i] = i <= pref ? i :
|
---|
546 | i > (nlen[0] - suff) ? (i + delta) : 0;
|
---|
547 | /* Here the magic is performed */
|
---|
548 | stone(class, slen[0], member, J, pref);
|
---|
549 | J[nlen[0] + 1] = nlen[1] + 1;
|
---|
550 |
|
---|
551 | free(class);
|
---|
552 | free(member);
|
---|
553 |
|
---|
554 | /* Both files are rescanned, in an effort to find any lines
|
---|
555 | * which, due to limitations intrinsic to any hashing algorithm,
|
---|
556 | * are different but ended up confounded as the same
|
---|
557 | */
|
---|
558 | for (i = 1; i <= nlen[0]; i++) {
|
---|
559 | if (!J[i])
|
---|
560 | continue;
|
---|
561 |
|
---|
562 | seek_ft(&ft[0], ix[0][i - 1]);
|
---|
563 | seek_ft(&ft[1], ix[1][J[i] - 1]);
|
---|
564 |
|
---|
565 | for (j = J[i]; i <= nlen[0] && J[i] == j; i++, j++) {
|
---|
566 | token_t tok0 = 0, tok1 = 0;
|
---|
567 | do {
|
---|
568 | tok0 = read_token(&ft[0], tok0);
|
---|
569 | tok1 = read_token(&ft[1], tok1);
|
---|
570 |
|
---|
571 | if (((tok0 ^ tok1) & TOK_EMPTY) != 0 /* one is empty (not both) */
|
---|
572 | || (!(tok0 & TOK_EMPTY) && TOK2CHAR(tok0) != TOK2CHAR(tok1))
|
---|
573 | ) {
|
---|
574 | J[i] = 0; /* Break the correspondence */
|
---|
575 | }
|
---|
576 | } while (!(tok0 & tok1 & TOK_EMPTY));
|
---|
577 | }
|
---|
578 | }
|
---|
579 |
|
---|
580 | return J;
|
---|
581 | }
|
---|
582 |
|
---|
583 | static bool diff(FILE* fp[2], char *file[2])
|
---|
584 | {
|
---|
585 | int nlen[2];
|
---|
586 | off_t *ix[2];
|
---|
587 | FILE_and_pos_t ft[2];
|
---|
588 | typedef struct { int a, b; } vec_t[2];
|
---|
589 | vec_t *vec = NULL;
|
---|
590 | int i = 1, j, k, idx = -1;
|
---|
591 | bool anychange = false;
|
---|
592 | int *J;
|
---|
593 |
|
---|
594 | ft[0].ft_fp = fp[0];
|
---|
595 | ft[1].ft_fp = fp[1];
|
---|
596 | /* note that ft[i].ft_pos is unintitalized, create_J()
|
---|
597 | * must not assume otherwise */
|
---|
598 | J = create_J(ft, nlen, ix);
|
---|
599 |
|
---|
600 | do {
|
---|
601 | bool nonempty = false;
|
---|
602 |
|
---|
603 | while (1) {
|
---|
604 | vec_t v;
|
---|
605 |
|
---|
606 | for (v[0].a = i; v[0].a <= nlen[0] && J[v[0].a] == J[v[0].a - 1] + 1; v[0].a++)
|
---|
607 | continue;
|
---|
608 | v[1].a = J[v[0].a - 1] + 1;
|
---|
609 |
|
---|
610 | for (v[0].b = v[0].a - 1; v[0].b < nlen[0] && !J[v[0].b + 1]; v[0].b++)
|
---|
611 | continue;
|
---|
612 | v[1].b = J[v[0].b + 1] - 1;
|
---|
613 | /*
|
---|
614 | * Indicate that there is a difference between lines a and b of the 'from' file
|
---|
615 | * to get to lines c to d of the 'to' file. If a is greater than b then there
|
---|
616 | * are no lines in the 'from' file involved and this means that there were
|
---|
617 | * lines appended (beginning at b). If c is greater than d then there are
|
---|
618 | * lines missing from the 'to' file.
|
---|
619 | */
|
---|
620 | if (v[0].a <= v[0].b || v[1].a <= v[1].b) {
|
---|
621 | /*
|
---|
622 | * If this change is more than 'context' lines from the
|
---|
623 | * previous change, dump the record and reset it.
|
---|
624 | */
|
---|
625 | int ct = (2 * opt_U_context) + 1;
|
---|
626 | if (idx >= 0
|
---|
627 | && v[0].a > vec[idx][0].b + ct
|
---|
628 | && v[1].a > vec[idx][1].b + ct
|
---|
629 | ) {
|
---|
630 | break;
|
---|
631 | }
|
---|
632 |
|
---|
633 | for (j = 0; j < 2; j++)
|
---|
634 | for (k = v[j].a; k < v[j].b; k++)
|
---|
635 | nonempty |= (ix[j][k+1] - ix[j][k] != 1);
|
---|
636 |
|
---|
637 | vec = xrealloc_vector(vec, 6, ++idx);
|
---|
638 | memcpy(vec[idx], v, sizeof(v));
|
---|
639 | }
|
---|
640 |
|
---|
641 | i = v[0].b + 1;
|
---|
642 | if (i > nlen[0])
|
---|
643 | break;
|
---|
644 | J[v[0].b] = v[1].b;
|
---|
645 | }
|
---|
646 | if (idx < 0 || ((option_mask32 & FLAG(B)) && !nonempty))
|
---|
647 | goto cont;
|
---|
648 | if (!(option_mask32 & FLAG(q))) {
|
---|
649 | int lowa;
|
---|
650 | vec_t span, *cvp = vec;
|
---|
651 |
|
---|
652 | if (!anychange) {
|
---|
653 | /* Print the context/unidiff header first time through */
|
---|
654 | printf("--- %s\n", label[0] ? label[0] : file[0]);
|
---|
655 | printf("+++ %s\n", label[1] ? label[1] : file[1]);
|
---|
656 | }
|
---|
657 |
|
---|
658 | printf("@@");
|
---|
659 | for (j = 0; j < 2; j++) {
|
---|
660 | int a = span[j].a = MAX(1, (*cvp)[j].a - opt_U_context);
|
---|
661 | int b = span[j].b = MIN(nlen[j], vec[idx][j].b + opt_U_context);
|
---|
662 |
|
---|
663 | printf(" %c%d", j ? '+' : '-', MIN(a, b));
|
---|
664 | if (a == b)
|
---|
665 | continue;
|
---|
666 | printf(",%d", (a < b) ? b - a + 1 : 0);
|
---|
667 | }
|
---|
668 | printf(" @@\n");
|
---|
669 | /*
|
---|
670 | * Output changes in "unified" diff format--the old and new lines
|
---|
671 | * are printed together.
|
---|
672 | */
|
---|
673 | for (lowa = span[0].a; ; lowa = (*cvp++)[0].b + 1) {
|
---|
674 | bool end = cvp > &vec[idx];
|
---|
675 | fetch(&ft[0], ix[0], lowa, end ? span[0].b : (*cvp)[0].a - 1, ' ');
|
---|
676 | if (end)
|
---|
677 | break;
|
---|
678 | for (j = 0; j < 2; j++)
|
---|
679 | fetch(&ft[j], ix[j], (*cvp)[j].a, (*cvp)[j].b, j ? '+' : '-');
|
---|
680 | }
|
---|
681 | }
|
---|
682 | anychange = true;
|
---|
683 | cont:
|
---|
684 | idx = -1;
|
---|
685 | } while (i <= nlen[0]);
|
---|
686 |
|
---|
687 | free(vec);
|
---|
688 | free(ix[0]);
|
---|
689 | free(ix[1]);
|
---|
690 | free(J);
|
---|
691 | return anychange;
|
---|
692 | }
|
---|
693 |
|
---|
694 | static int diffreg(char *file[2])
|
---|
695 | {
|
---|
696 | FILE *fp[2];
|
---|
697 | bool binary = false, differ = false;
|
---|
698 | int status = STATUS_SAME, i;
|
---|
699 |
|
---|
700 | fp[0] = stdin;
|
---|
701 | fp[1] = stdin;
|
---|
702 | for (i = 0; i < 2; i++) {
|
---|
703 | int fd = open_or_warn_stdin(file[i]);
|
---|
704 | if (fd == -1)
|
---|
705 | goto out;
|
---|
706 | /* Our diff implementation is using seek.
|
---|
707 | * When we meet non-seekable file, we must make a temp copy.
|
---|
708 | */
|
---|
709 | if (lseek(fd, 0, SEEK_SET) == -1 && errno == ESPIPE) {
|
---|
710 | char name[] = "/tmp/difXXXXXX";
|
---|
711 | int fd_tmp = xmkstemp(name);
|
---|
712 |
|
---|
713 | unlink(name);
|
---|
714 | if (bb_copyfd_eof(fd, fd_tmp) < 0)
|
---|
715 | xfunc_die();
|
---|
716 | if (fd) /* Prevents closing of stdin */
|
---|
717 | close(fd);
|
---|
718 | fd = fd_tmp;
|
---|
719 | }
|
---|
720 | fp[i] = fdopen(fd, "r");
|
---|
721 | }
|
---|
722 |
|
---|
723 | while (1) {
|
---|
724 | const size_t sz = COMMON_BUFSIZE / 2;
|
---|
725 | char *const buf0 = bb_common_bufsiz1;
|
---|
726 | char *const buf1 = buf0 + sz;
|
---|
727 | int j, k;
|
---|
728 | i = fread(buf0, 1, sz, fp[0]);
|
---|
729 | j = fread(buf1, 1, sz, fp[1]);
|
---|
730 | if (i != j) {
|
---|
731 | differ = true;
|
---|
732 | i = MIN(i, j);
|
---|
733 | }
|
---|
734 | if (i == 0)
|
---|
735 | break;
|
---|
736 | for (k = 0; k < i; k++) {
|
---|
737 | if (!buf0[k] || !buf1[k])
|
---|
738 | binary = true;
|
---|
739 | if (buf0[k] != buf1[k])
|
---|
740 | differ = true;
|
---|
741 | }
|
---|
742 | }
|
---|
743 | if (differ) {
|
---|
744 | if (binary && !(option_mask32 & FLAG(a)))
|
---|
745 | status = STATUS_BINARY;
|
---|
746 | else if (diff(fp, file))
|
---|
747 | status = STATUS_DIFFER;
|
---|
748 | }
|
---|
749 | if (status != STATUS_SAME)
|
---|
750 | exit_status |= 1;
|
---|
751 | out:
|
---|
752 | fclose_if_not_stdin(fp[0]);
|
---|
753 | fclose_if_not_stdin(fp[1]);
|
---|
754 |
|
---|
755 | return status;
|
---|
756 | }
|
---|
757 |
|
---|
758 | static void print_status(int status, char *path[2])
|
---|
759 | {
|
---|
760 | switch (status) {
|
---|
761 | case STATUS_BINARY:
|
---|
762 | case STATUS_DIFFER:
|
---|
763 | if ((option_mask32 & FLAG(q)) || status == STATUS_BINARY)
|
---|
764 | printf("Files %s and %s differ\n", path[0], path[1]);
|
---|
765 | break;
|
---|
766 | case STATUS_SAME:
|
---|
767 | if (option_mask32 & FLAG(s))
|
---|
768 | printf("Files %s and %s are identical\n", path[0], path[1]);
|
---|
769 | break;
|
---|
770 | }
|
---|
771 | }
|
---|
772 |
|
---|
773 | #if ENABLE_FEATURE_DIFF_DIR
|
---|
774 | struct dlist {
|
---|
775 | size_t len;
|
---|
776 | int s, e;
|
---|
777 | char **dl;
|
---|
778 | };
|
---|
779 |
|
---|
780 | /* This function adds a filename to dl, the directory listing. */
|
---|
781 | static int FAST_FUNC add_to_dirlist(const char *filename,
|
---|
782 | struct stat *sb UNUSED_PARAM,
|
---|
783 | void *userdata, int depth UNUSED_PARAM)
|
---|
784 | {
|
---|
785 | struct dlist *const l = userdata;
|
---|
786 | const char *file = filename + l->len;
|
---|
787 | while (*file == '/')
|
---|
788 | file++;
|
---|
789 | l->dl = xrealloc_vector(l->dl, 6, l->e);
|
---|
790 | l->dl[l->e] = xstrdup(file);
|
---|
791 | l->e++;
|
---|
792 | return TRUE;
|
---|
793 | }
|
---|
794 |
|
---|
795 | /* If recursion is not set, this function adds the directory
|
---|
796 | * to the list and prevents recursive_action from recursing into it.
|
---|
797 | */
|
---|
798 | static int FAST_FUNC skip_dir(const char *filename,
|
---|
799 | struct stat *sb, void *userdata,
|
---|
800 | int depth)
|
---|
801 | {
|
---|
802 | if (!(option_mask32 & FLAG(r)) && depth) {
|
---|
803 | add_to_dirlist(filename, sb, userdata, depth);
|
---|
804 | return SKIP;
|
---|
805 | }
|
---|
806 | if (!(option_mask32 & FLAG(N))) {
|
---|
807 | /* -r without -N: no need to recurse into dirs
|
---|
808 | * which do not exist on the "other side".
|
---|
809 | * Testcase: diff -r /tmp /
|
---|
810 | * (it would recurse deep into /proc without this code) */
|
---|
811 | struct dlist *const l = userdata;
|
---|
812 | filename += l->len;
|
---|
813 | if (filename[0]) {
|
---|
814 | struct stat osb;
|
---|
815 | char *othername = concat_path_file(G.other_dir, filename);
|
---|
816 | int r = stat(othername, &osb);
|
---|
817 | free(othername);
|
---|
818 | if (r != 0 || !S_ISDIR(osb.st_mode)) {
|
---|
819 | /* other dir doesn't have similarly named
|
---|
820 | * directory, don't recurse; return 1 upon
|
---|
821 | * exit, just like diffutils' diff */
|
---|
822 | exit_status |= 1;
|
---|
823 | return SKIP;
|
---|
824 | }
|
---|
825 | }
|
---|
826 | }
|
---|
827 | return TRUE;
|
---|
828 | }
|
---|
829 |
|
---|
830 | static void diffdir(char *p[2], const char *s_start)
|
---|
831 | {
|
---|
832 | struct dlist list[2];
|
---|
833 | int i;
|
---|
834 |
|
---|
835 | memset(&list, 0, sizeof(list));
|
---|
836 | for (i = 0; i < 2; i++) {
|
---|
837 | /*list[i].s = list[i].e = 0; - memset did it */
|
---|
838 | /*list[i].dl = NULL; */
|
---|
839 |
|
---|
840 | G.other_dir = p[1 - i];
|
---|
841 | /* We need to trim root directory prefix.
|
---|
842 | * Using list.len to specify its length,
|
---|
843 | * add_to_dirlist will remove it. */
|
---|
844 | list[i].len = strlen(p[i]);
|
---|
845 | recursive_action(p[i], ACTION_RECURSE | ACTION_FOLLOWLINKS,
|
---|
846 | add_to_dirlist, skip_dir, &list[i], 0);
|
---|
847 | /* Sort dl alphabetically.
|
---|
848 | * GNU diff does this ignoring any number of trailing dots.
|
---|
849 | * We don't, so for us dotted files almost always are
|
---|
850 | * first on the list.
|
---|
851 | */
|
---|
852 | qsort_string_vector(list[i].dl, list[i].e);
|
---|
853 | /* If -S was set, find the starting point. */
|
---|
854 | if (!s_start)
|
---|
855 | continue;
|
---|
856 | while (list[i].s < list[i].e && strcmp(list[i].dl[list[i].s], s_start) < 0)
|
---|
857 | list[i].s++;
|
---|
858 | }
|
---|
859 | /* Now that both dirlist1 and dirlist2 contain sorted directory
|
---|
860 | * listings, we can start to go through dirlist1. If both listings
|
---|
861 | * contain the same file, then do a normal diff. Otherwise, behaviour
|
---|
862 | * is determined by whether the -N flag is set. */
|
---|
863 | while (1) {
|
---|
864 | char *dp[2];
|
---|
865 | int pos;
|
---|
866 | int k;
|
---|
867 |
|
---|
868 | dp[0] = list[0].s < list[0].e ? list[0].dl[list[0].s] : NULL;
|
---|
869 | dp[1] = list[1].s < list[1].e ? list[1].dl[list[1].s] : NULL;
|
---|
870 | if (!dp[0] && !dp[1])
|
---|
871 | break;
|
---|
872 | pos = !dp[0] ? 1 : (!dp[1] ? -1 : strcmp(dp[0], dp[1]));
|
---|
873 | k = pos > 0;
|
---|
874 | if (pos && !(option_mask32 & FLAG(N))) {
|
---|
875 | printf("Only in %s: %s\n", p[k], dp[k]);
|
---|
876 | exit_status |= 1;
|
---|
877 | } else {
|
---|
878 | char *fullpath[2], *path[2]; /* if -N */
|
---|
879 |
|
---|
880 | for (i = 0; i < 2; i++) {
|
---|
881 | if (pos == 0 || i == k) {
|
---|
882 | path[i] = fullpath[i] = concat_path_file(p[i], dp[i]);
|
---|
883 | stat(fullpath[i], &stb[i]);
|
---|
884 | } else {
|
---|
885 | fullpath[i] = concat_path_file(p[i], dp[1 - i]);
|
---|
886 | path[i] = (char *)bb_dev_null;
|
---|
887 | }
|
---|
888 | }
|
---|
889 | if (pos)
|
---|
890 | stat(fullpath[k], &stb[1 - k]);
|
---|
891 |
|
---|
892 | if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode))
|
---|
893 | printf("Common subdirectories: %s and %s\n", fullpath[0], fullpath[1]);
|
---|
894 | else if (!S_ISREG(stb[0].st_mode) && !S_ISDIR(stb[0].st_mode))
|
---|
895 | printf("File %s is not a regular file or directory and was skipped\n", fullpath[0]);
|
---|
896 | else if (!S_ISREG(stb[1].st_mode) && !S_ISDIR(stb[1].st_mode))
|
---|
897 | printf("File %s is not a regular file or directory and was skipped\n", fullpath[1]);
|
---|
898 | else if (S_ISDIR(stb[0].st_mode) != S_ISDIR(stb[1].st_mode)) {
|
---|
899 | if (S_ISDIR(stb[0].st_mode))
|
---|
900 | printf("File %s is a %s while file %s is a %s\n", fullpath[0], "directory", fullpath[1], "regular file");
|
---|
901 | else
|
---|
902 | printf("File %s is a %s while file %s is a %s\n", fullpath[0], "regular file", fullpath[1], "directory");
|
---|
903 | } else
|
---|
904 | print_status(diffreg(path), fullpath);
|
---|
905 |
|
---|
906 | free(fullpath[0]);
|
---|
907 | free(fullpath[1]);
|
---|
908 | }
|
---|
909 | free(dp[k]);
|
---|
910 | list[k].s++;
|
---|
911 | if (pos == 0) {
|
---|
912 | free(dp[1 - k]);
|
---|
913 | list[1 - k].s++;
|
---|
914 | }
|
---|
915 | }
|
---|
916 | if (ENABLE_FEATURE_CLEAN_UP) {
|
---|
917 | free(list[0].dl);
|
---|
918 | free(list[1].dl);
|
---|
919 | }
|
---|
920 | }
|
---|
921 | #endif
|
---|
922 |
|
---|
923 | #if ENABLE_FEATURE_DIFF_LONG_OPTIONS
|
---|
924 | static const char diff_longopts[] ALIGN1 =
|
---|
925 | "ignore-case\0" No_argument "i"
|
---|
926 | "ignore-tab-expansion\0" No_argument "E"
|
---|
927 | "ignore-space-change\0" No_argument "b"
|
---|
928 | "ignore-all-space\0" No_argument "w"
|
---|
929 | "ignore-blank-lines\0" No_argument "B"
|
---|
930 | "text\0" No_argument "a"
|
---|
931 | "unified\0" Required_argument "U"
|
---|
932 | "label\0" Required_argument "L"
|
---|
933 | "show-c-function\0" No_argument "p"
|
---|
934 | "brief\0" No_argument "q"
|
---|
935 | "expand-tabs\0" No_argument "t"
|
---|
936 | "initial-tab\0" No_argument "T"
|
---|
937 | "recursive\0" No_argument "r"
|
---|
938 | "new-file\0" No_argument "N"
|
---|
939 | "report-identical-files\0" No_argument "s"
|
---|
940 | "starting-file\0" Required_argument "S"
|
---|
941 | "minimal\0" No_argument "d"
|
---|
942 | ;
|
---|
943 | #endif
|
---|
944 |
|
---|
945 | int diff_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
946 | int diff_main(int argc UNUSED_PARAM, char **argv)
|
---|
947 | {
|
---|
948 | int gotstdin = 0, i;
|
---|
949 | char *file[2], *s_start = NULL;
|
---|
950 | llist_t *L_arg = NULL;
|
---|
951 |
|
---|
952 | INIT_G();
|
---|
953 |
|
---|
954 | /* exactly 2 params; collect multiple -L <label>; -U N */
|
---|
955 | opt_complementary = "=2:L::U+";
|
---|
956 | #if ENABLE_FEATURE_DIFF_LONG_OPTIONS
|
---|
957 | applet_long_options = diff_longopts;
|
---|
958 | #endif
|
---|
959 | getopt32(argv, "abdiL:NqrsS:tTU:wupBE",
|
---|
960 | &L_arg, &s_start, &opt_U_context);
|
---|
961 | argv += optind;
|
---|
962 | while (L_arg)
|
---|
963 | label[!!label[0]] = llist_pop(&L_arg);
|
---|
964 | xfunc_error_retval = 2;
|
---|
965 | for (i = 0; i < 2; i++) {
|
---|
966 | file[i] = argv[i];
|
---|
967 | /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
|
---|
968 | if (LONE_DASH(file[i])) {
|
---|
969 | fstat(STDIN_FILENO, &stb[i]);
|
---|
970 | gotstdin++;
|
---|
971 | } else
|
---|
972 | xstat(file[i], &stb[i]);
|
---|
973 | }
|
---|
974 | xfunc_error_retval = 1;
|
---|
975 | if (gotstdin && (S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode)))
|
---|
976 | bb_error_msg_and_die("can't compare stdin to a directory");
|
---|
977 |
|
---|
978 | /* Compare metadata to check if the files are the same physical file.
|
---|
979 | *
|
---|
980 | * Comment from diffutils source says:
|
---|
981 | * POSIX says that two files are identical if st_ino and st_dev are
|
---|
982 | * the same, but many file systems incorrectly assign the same (device,
|
---|
983 | * inode) pair to two distinct files, including:
|
---|
984 | * GNU/Linux NFS servers that export all local file systems as a
|
---|
985 | * single NFS file system, if a local device number (st_dev) exceeds
|
---|
986 | * 255, or if a local inode number (st_ino) exceeds 16777215.
|
---|
987 | */
|
---|
988 | if (ENABLE_DESKTOP
|
---|
989 | && stb[0].st_ino == stb[1].st_ino
|
---|
990 | && stb[0].st_dev == stb[1].st_dev
|
---|
991 | && stb[0].st_size == stb[1].st_size
|
---|
992 | && stb[0].st_mtime == stb[1].st_mtime
|
---|
993 | && stb[0].st_ctime == stb[1].st_ctime
|
---|
994 | && stb[0].st_mode == stb[1].st_mode
|
---|
995 | && stb[0].st_nlink == stb[1].st_nlink
|
---|
996 | && stb[0].st_uid == stb[1].st_uid
|
---|
997 | && stb[0].st_gid == stb[1].st_gid
|
---|
998 | ) {
|
---|
999 | /* files are physically the same; no need to compare them */
|
---|
1000 | return STATUS_SAME;
|
---|
1001 | }
|
---|
1002 |
|
---|
1003 | if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode)) {
|
---|
1004 | #if ENABLE_FEATURE_DIFF_DIR
|
---|
1005 | diffdir(file, s_start);
|
---|
1006 | #else
|
---|
1007 | bb_error_msg_and_die("no support for directory comparison");
|
---|
1008 | #endif
|
---|
1009 | } else {
|
---|
1010 | bool dirfile = S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode);
|
---|
1011 | bool dir = S_ISDIR(stb[1].st_mode);
|
---|
1012 | if (dirfile) {
|
---|
1013 | const char *slash = strrchr(file[!dir], '/');
|
---|
1014 | file[dir] = concat_path_file(file[dir], slash ? slash + 1 : file[!dir]);
|
---|
1015 | xstat(file[dir], &stb[dir]);
|
---|
1016 | }
|
---|
1017 | /* diffreg can get non-regular files here */
|
---|
1018 | print_status(gotstdin > 1 ? STATUS_SAME : diffreg(file), file);
|
---|
1019 |
|
---|
1020 | if (dirfile)
|
---|
1021 | free(file[dir]);
|
---|
1022 | }
|
---|
1023 |
|
---|
1024 | return exit_status;
|
---|
1025 | }
|
---|