File: dedup.cpp
   1 /*
   2 The MIT License (MIT)
   3 
   4 Copyright © 2020-2025 pacman64
   5 
   6 Permission is hereby granted, free of charge, to any person obtaining a copy of
   7 this software and associated documentation files (the “Software”), to deal
   8 in the Software without restriction, including without limitation the rights to
   9 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  10 of the Software, and to permit persons to whom the Software is furnished to do
  11 so, subject to the following conditions:
  12 
  13 The above copyright notice and this permission notice shall be included in all
  14 copies or substantial portions of the Software.
  15 
  16 THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22 SOFTWARE.
  23 */
  24 
  25 /*
  26 You can build this command-line app by running
  27 
  28 g++ -Wall -O2 -s -o dedup dedup.cpp
  29 */
  30 
  31 #include <fstream>
  32 #include <iostream>
  33 #include <new>
  34 #include <string>
  35 
  36 #ifdef FLAT_SET
  37 #include <flat_set>
  38 #else
  39 #include <set>
  40 #endif
  41 
  42 using namespace std;
  43 
  44 const string info = ""
  45 "dedup [files...]\n"
  46 "\n"
  47 "DEDUPlicate lines, emitting each distinct line once, on first occurrence.\n"
  48 "Unlike `uniq`, it doesn't require pre-sorted lines to work correctly, and\n"
  49 "keeps lines in their original order."
  50 "";
  51 
  52 #ifdef FLAT_SET
  53 typedef flat_set<string> string_set;
  54 #else
  55 typedef set<string> string_set;
  56 #endif
  57 
  58 void handle_input(istream& in, string& line, string_set& seen) {
  59     const auto& not_found = seen.end();
  60     while (!cout.eof() && getline(in, line)) {
  61         if (seen.find(line) == not_found) {
  62             cout << line << endl;
  63             seen.insert(line);
  64         }
  65     }
  66 }
  67 
  68 bool handle_file(const char* path, string& line, string_set& seen) {
  69     ifstream f(path);
  70     if (f.is_open()) {
  71         handle_input(f, line, seen);
  72         return true;
  73     }
  74 
  75     cerr << "\x1b[31mcan't open file named '" << path << "'\x1b[0m" << endl;
  76     return false;
  77 }
  78 
  79 // run returns the number of errors
  80 int run(size_t argc, char** argv) {
  81     string line;
  82     string_set seen;
  83 
  84     if (argc > 1) {
  85         const string& s = argv[1];
  86         if (s == "-h" || s == "-help" || s == "--h" || s == "--help") {
  87             cout << info;
  88             return 0;
  89         }
  90     }
  91 
  92     cin.tie(NULL);
  93     ios_base::sync_with_stdio(false);
  94 
  95     size_t dashes = 0;
  96     size_t errors = 0;
  97     for (size_t i = 1; i < argc && !cout.eof(); i++) {
  98         if (argv[i][0] == '-' && argv[i][1] == 0) {
  99             dashes++;
 100             if (dashes < 2) {
 101                 handle_input(cin, line, seen);
 102             }
 103             continue;
 104         }
 105 
 106         if (!handle_file(argv[i], line, seen)) {
 107             errors++;
 108         }
 109     }
 110 
 111     if (argc < 2) {
 112         handle_input(cin, line, seen);
 113     }
 114 
 115     return errors;
 116 }
 117 
 118 int main(int argc, char** argv) {
 119     try {
 120         return run(argc, argv) == 0 ? 0 : 1;
 121     } catch (const bad_alloc& e) {
 122         cerr << "\x1b[31mout of memory\x1b[0m" << endl;
 123         return 1;
 124     }
 125 }