File: tcatl.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 -O2 -o ./tcatl ./tcatl.c 29 */ 30 31 #include <fcntl.h> 32 #include <stdbool.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 37 #ifdef _WIN32 38 #include <windows.h> 39 #endif 40 41 const char* info = "" 42 "tcatl [filenames...]\n" 43 "\n" 44 "Title and Concatenate lines emits lines from all the named sources given,\n" 45 "preceding each file's contents with its name, using an ANSI reverse style.\n" 46 "\n" 47 "The name `-` stands for the standard input. When no names are given, the\n" 48 "standard input is used by default.\n" 49 ""; 50 51 const char* no_line_memory_msg = "can't get enough memory to read lines"; 52 53 // slice is a growable region of bytes in memory 54 typedef struct slice { 55 // ptr is the starting place of the region 56 unsigned char* ptr; 57 58 // len is how many bytes are currently being used 59 size_t len; 60 61 // cap is how many bytes the memory region has available 62 size_t cap; 63 } slice; 64 65 bool starts_with_bom(const unsigned char* b, const size_t n) { 66 return (n >= 3 && b[0] == 0xef && b[1] == 0xbb && b[2] == 0xbf); 67 } 68 69 // handle_reader skips leading UTF-8 BOMs (byte-order marks), and turns all 70 // CR-LF pairs into single LF bytes 71 bool handle_reader(FILE* w, FILE* r, slice* line) { 72 slice trimmed; 73 74 for (size_t i = 0; !feof(w); i++) { 75 int len = getline((char**)&line->ptr, &line->cap, r); 76 if (len < 0) { 77 break; 78 } 79 80 if (line->ptr == NULL) { 81 putc('\n', w); 82 fflush(w); 83 84 fprintf(stderr, "\x1b[31m%s\x1b[0m\n", no_line_memory_msg); 85 exit(1); 86 } 87 88 line->len = len; 89 trimmed.ptr = line->ptr; 90 trimmed.len = line->len; 91 92 // get rid of leading UTF-8 BOM (byte-order mark) if 1st line has it 93 if (i == 0 && starts_with_bom(trimmed.ptr, trimmed.len)) { 94 trimmed.ptr += 3; 95 trimmed.len -= 3; 96 len = trimmed.len; 97 } 98 99 const unsigned char* p = trimmed.ptr; 100 // get rid of trailing line-feeds and CRLF end-of-line byte-pairs 101 if (len >= 2 && p[len - 2] == '\r' && p[len - 1] == '\n') { 102 trimmed.len -= 2; 103 } else if (len >= 1 && p[len - 1] == '\n') { 104 trimmed.len--; 105 } 106 107 fwrite(trimmed.ptr, trimmed.len, 1, w); 108 putc('\n', w); 109 fflush(w); 110 } 111 112 return true; 113 } 114 115 // handle_file handles data from the filename given; returns false only when 116 // the file can't be opened 117 bool handle_file(FILE* w, char* fname, slice* line) { 118 fprintf(w, "\x1b[7m%s\x1b[0m\n", fname); 119 fflush(w); 120 121 FILE* f = fopen(fname, "rb"); 122 if (f == NULL) { 123 fprintf(stderr, "\x1b[31mcan't open file named %s\x1b[0m\n", fname); 124 return false; 125 } 126 127 const bool ok = handle_reader(w, f, line); 128 fclose(f); 129 return ok; 130 } 131 132 // run returns the number of errors 133 int run(int argc, char** argv, FILE* w) { 134 size_t dashes = 0; 135 for (int i = 1; i < argc; i++) { 136 if (argv[i][0] == '-' && argv[i][1] == 0) { 137 dashes++; 138 } 139 } 140 141 if (dashes > 1) { 142 const char* msg = "can't use the standard input (dash) more than once"; 143 fprintf(stderr, "\x1b[31m%s\x1b[0m\n", msg); 144 return 1; 145 } 146 147 slice line; 148 line.len = 0; 149 line.cap = 32 * 1024; 150 line.ptr = malloc(line.cap); 151 152 if (line.ptr == NULL) { 153 fprintf(stderr, "\x1b[31m%s\x1b[0m\n", no_line_memory_msg); 154 return 1; 155 } 156 157 // use stdin when not given any filepaths 158 if (argc <= 1) { 159 fputs("\x1b[7m-\x1b[0m\n", w); 160 fflush(w); 161 162 handle_reader(w, stdin, &line); 163 free(line.ptr); 164 return 0; 165 } 166 167 size_t errors = 0; 168 for (int i = 1; i < argc && !feof(stdout); i++) { 169 if (argv[i][0] == '-' && argv[i][1] == 0) { 170 fputs("\x1b[7m-\x1b[0m\n", w); 171 fflush(w); 172 173 if (!handle_reader(w, stdin, &line)) { 174 errors++; 175 } 176 continue; 177 } 178 179 if (!handle_file(w, argv[i], &line)) { 180 errors++; 181 } 182 } 183 184 free(line.ptr); 185 return errors; 186 } 187 188 int main(int argc, char** argv) { 189 #ifdef _WIN32 190 setmode(fileno(stdin), O_BINARY); 191 // ensure output lines end in LF instead of CRLF on windows 192 setmode(fileno(stdout), O_BINARY); 193 setmode(fileno(stderr), O_BINARY); 194 #endif 195 196 if (argc > 1) { 197 if ( 198 strcmp(argv[1], "-h") == 0 || 199 strcmp(argv[1], "-help") == 0 || 200 strcmp(argv[1], "--h") == 0 || 201 strcmp(argv[1], "--help") == 0 202 ) { 203 fprintf(stdout, "%s", info); 204 return 0; 205 } 206 } 207 208 return run(argc, argv, stdout) == 0 ? 0 : 1; 209 }