diff --git a/Userland/Utilities/tac.cpp b/Userland/Utilities/tac.cpp new file mode 100644 index 0000000000..f28b0a02a7 --- /dev/null +++ b/Userland/Utilities/tac.cpp @@ -0,0 +1,69 @@ +/* + * Copyright (c) 2021, Federico Guerinoni + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include + +void print_lines(const Vector& vec); + +int main(int argc, char** argv) +{ + if (pledge("stdio rpath", nullptr) < 0) { + perror("pledge"); + return 1; + } + + const char* path = nullptr; + Core::ArgsParser args_parser; + args_parser.set_general_help("Concatenate files or pipes to stdout, last line first."); + args_parser.add_positional_argument(path, "File path", "path", Core::ArgsParser::Required::No); + args_parser.parse(argc, argv); + + RefPtr file; + if (path == nullptr) { + file = Core::File::standard_input(); + } else { + auto file_or_error = Core::File::open(path, Core::File::ReadOnly); + if (file_or_error.is_error()) { + warnln("Failed to open {}: {}", path, file_or_error.error()); + return 1; + } + file = file_or_error.value(); + } + + Vector lines; + while (file->can_read_line()) { + auto line = file->read_line(); + lines.append(line); + } + + for (int i = lines.size() - 1; i >= 0; --i) + outln("{}", lines[i]); + + return 0; +}