File: tally.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 tally tally.cpp
  29 */
  30 
  31 #include <algorithm>
  32 #include <cstdint>
  33 #include <cstring>
  34 #include <fstream>
  35 #include <iostream>
  36 #include <map>
  37 #include <new>
  38 #include <string>
  39 #include <vector>
  40 
  41 using namespace std;
  42 
  43 const string info = ""
  44 "tally [files...]\n"
  45 "\n"
  46 "Tally/count each distinct line. The output is a TSV table, with headers.\n"
  47 "";
  48 
  49 typedef map<string, uint64_t> string_tally;
  50 
  51 void handle_input(istream& in, string& line, string_tally& tally) {
  52     while (getline(in, line)) {
  53         tally[line]++;
  54     }
  55 }
  56 
  57 bool handle_file(const char* path, string& line, string_tally& tally) {
  58     ifstream f(path);
  59     if (f.is_open()) {
  60         handle_input(f, line, tally);
  61         return true;
  62     }
  63 
  64     cerr << "\x1b[31mcan't open file named '" << path << "'\x1b[0m" << endl;
  65     return false;
  66 }
  67 
  68 // run returns the number of errors
  69 int run(int argc, char** argv) {
  70     string line;
  71     string_tally tally;
  72 
  73     if (argc > 1) {
  74         if (
  75             strcmp(argv[1], "-h") == 0 ||
  76             strcmp(argv[1], "-help") == 0 ||
  77             strcmp(argv[1], "--h") == 0 ||
  78             strcmp(argv[1], "--help") == 0
  79         ) {
  80             cout << info;
  81             return 0;
  82         }
  83     }
  84 
  85     size_t dashes = 0;
  86     for (int i = 1; i < argc; i++) {
  87         if (argv[i][0] == '-' && argv[i][1] == 0) {
  88             dashes++;
  89         }
  90     }
  91 
  92     if (dashes > 1) {
  93         cerr << "\x1b[31mcan't use dash (stdin) more than once\x1b[0m" << endl;
  94         return 1;
  95     }
  96 
  97     cin.tie(NULL);
  98     ios_base::sync_with_stdio(false);
  99 
 100     cout << "value\ttally" << endl;
 101 
 102     size_t errors = 0;
 103     for (int i = 1; i < argc; i++) {
 104         if (argv[i][0] == '-' && argv[i][1] == 0) {
 105             handle_input(cin, line, tally);
 106             continue;
 107         }
 108 
 109         if (!handle_file(argv[i], line, tally)) {
 110             errors++;
 111         }
 112     }
 113 
 114     if (argc < 2) {
 115         handle_input(cin, line, tally);
 116     }
 117 
 118     vector<string> sorted;
 119     sorted.reserve(tally.size());
 120     for (auto kv = tally.begin(); kv != tally.end(); kv++) {
 121         sorted.push_back(kv->first);
 122     }
 123 
 124     sort(sorted.begin(), sorted.end(), [&tally](const auto& x, const auto& y) {
 125         auto a = tally[x];
 126         auto b = tally[y];
 127         if (a > b) {
 128             return true;
 129         }
 130         return x < y;
 131     });
 132 
 133     for (const auto& k : sorted) {
 134         cout << k << '\t' << tally[k] << endl;
 135         if (cout.eof()) {
 136             break;
 137         }
 138     }
 139 
 140     return errors++;
 141 }
 142 
 143 int main(int argc, char** argv) {
 144     try {
 145         return run(argc, argv) == 0 ? 0 : 1;
 146     } catch (const bad_alloc& e) {
 147         cerr << "\x1b[31mout of memory\x1b[0m" << endl;
 148         return 1;
 149     }
 150 }