File: catl.c
   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 cc -Wall -s -O3 -march=native -mtune=native -flto -o ./catl ./catl.c
  29 */
  30 
  31 #include <stdbool.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36 
  37 #ifdef _WIN32
  38 #include <fcntl.h>
  39 #include <windows.h>
  40 #endif
  41 
  42 #ifdef RED_ERRORS
  43 #define ERROR_STYLE "\x1b[38;2;204;0;0m"
  44 #ifdef __APPLE__
  45 #define ERROR_STYLE "\x1b[31m"
  46 #endif
  47 #define RESET_STYLE "\x1b[0m"
  48 #else
  49 #define ERROR_STYLE
  50 #define RESET_STYLE
  51 #endif
  52 
  53 #define ERROR_LINE(MSG) (ERROR_STYLE MSG RESET_STYLE "\n")
  54 
  55 #define BAD_ALLOC 2
  56 
  57 #ifndef IBUF_SIZE
  58 #define IBUF_SIZE (32 * 1024)
  59 #endif
  60 
  61 const char* info = ""
  62 "catl [filenames...]\n"
  63 "\n"
  64 "Concatenate lines from all the named sources given. The name `-` stands for\n"
  65 "the standard input. When no names are given, the standard input is used by\n"
  66 "default.\n"
  67 "";
  68 
  69 // slice is a growable region of bytes in memory
  70 typedef struct slice {
  71     // ptr is the starting place of the region
  72     unsigned char* ptr;
  73 
  74     // cap is how many bytes the memory region has available
  75     size_t cap;
  76 } slice;
  77 
  78 void handle_reader_faster(FILE* w, FILE* r) {
  79     unsigned char buf[IBUF_SIZE];
  80     unsigned char last = '\n';
  81 
  82     while (!feof(w)) {
  83         size_t len = fread(buf, sizeof(buf[0]), sizeof(buf), r);
  84         if (len < 1) {
  85             break;
  86         }
  87 
  88         fwrite(buf, 1, len, w);
  89         last = buf[len - 1];
  90     }
  91 
  92     if (last != '\n') {
  93         fputc('\n', w);
  94     }
  95 }
  96 
  97 void handle_reader(FILE* w, FILE* r, slice* line, bool live_lines) {
  98     if (!live_lines) {
  99         handle_reader_faster(w, r);
 100         return;
 101     }
 102 
 103     while (!feof(w)) {
 104         ssize_t len = getline((char**)&line->ptr, &line->cap, r);
 105         if (line->ptr == NULL) {
 106             fprintf(stderr, "\n");
 107             fprintf(stderr, ERROR_LINE("out of memory"));
 108             exit(BAD_ALLOC);
 109         }
 110 
 111         if (len < 0) {
 112             break;
 113         }
 114 
 115         fwrite(line->ptr, 1, len, w);
 116         const bool has_lf = len >= 1 && line->ptr[len - 1] == '\n';
 117         if (!has_lf) {
 118             fputc('\n', w);
 119         }
 120         fflush(w);
 121     }
 122 }
 123 
 124 // handle_file handles data from the filename given; returns false only when
 125 // the file can't be opened
 126 bool handle_file(FILE* w, const char* path, slice* line, bool live_lines) {
 127     FILE* f = fopen(path, "rb");
 128     if (f == NULL) {
 129         fprintf(stderr, ERROR_LINE("can't open file named '%s'"), path);
 130         return false;
 131     }
 132 
 133     handle_reader(w, f, line, live_lines);
 134     fclose(f);
 135     return true;
 136 }
 137 
 138 // run returns the number of errors
 139 int run(char** args, size_t nargs, FILE* w, bool live_lines) {
 140     size_t dashes = 0;
 141     for (size_t i = 0; i < nargs; i++) {
 142         if (args[i][0] == '-' && args[i][1] == 0) {
 143             dashes++;
 144         }
 145     }
 146 
 147     if (dashes > 1) {
 148         const char* m = "can't use the standard input (dash) more than once";
 149         fprintf(stderr, ERROR_LINE("%s"), m);
 150         return 1;
 151     }
 152 
 153     slice line;
 154     line.ptr = NULL;
 155     line.cap = 0;
 156 
 157     if (live_lines) {
 158         line.cap = 32 * 1024;
 159         line.ptr = malloc(line.cap);
 160         if (line.ptr == NULL) {
 161             fprintf(stderr, ERROR_LINE("out of memory"));
 162             exit(BAD_ALLOC);
 163         }
 164     }
 165 
 166     size_t errors = 0;
 167     for (size_t i = 0; i < nargs && !feof(w); i++) {
 168         if (args[i][0] == '-' && args[i][1] == 0) {
 169             handle_reader(w, stdin, &line, live_lines);
 170             continue;
 171         }
 172 
 173         if (!handle_file(w, args[i], &line, live_lines)) {
 174             errors++;
 175         }
 176     }
 177 
 178     // use stdin when not given any filepaths
 179     if (nargs < 1) {
 180         handle_reader(w, stdin, &line, live_lines);
 181     }
 182 
 183     free(line.ptr);
 184     return errors;
 185 }
 186 
 187 int main(int argc, char** argv) {
 188 #ifdef _WIN32
 189     setmode(fileno(stdin), O_BINARY);
 190     // ensure output lines end in LF instead of CRLF on windows
 191     setmode(fileno(stdout), O_BINARY);
 192     setmode(fileno(stderr), O_BINARY);
 193 #endif
 194 
 195     if (argc > 1) {
 196         if (
 197             strcmp(argv[1], "-h") == 0 ||
 198             strcmp(argv[1], "-help") == 0 ||
 199             strcmp(argv[1], "--h") == 0 ||
 200             strcmp(argv[1], "--help") == 0
 201         ) {
 202             fprintf(stdout, "%s", info);
 203             return 0;
 204         }
 205     }
 206 
 207     size_t nargs = argc - 1;
 208     char** args = argv + 1;
 209     if (nargs > 0 && strcmp(args[0], "--") == 0) {
 210         nargs--;
 211         args++;
 212     }
 213 
 214     const bool live_lines = lseek(fileno(stdout), 0, SEEK_CUR) != 0;
 215     if (!live_lines) {
 216         setvbuf(stdout, NULL, _IOFBF, 0);
 217     }
 218     return run(args, nargs, stdout, live_lines) == 0 ? 0 : 1;
 219 }