options parsing

.gitignore

@@ -0,0 +1,3 @@
+/.idea
+/cmake-build-debug
+/cmake-build-release

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.8)
+project(logrotee)
+
+set(CMAKE_CXX_STANDARD 17)
+
+set(SOURCE_FILES logrotee.cpp)
+add_executable(logrotee ${SOURCE_FILES})

LICENSE

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+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+                    Version 2, December 2004
+
+ Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
+
+ Everyone is permitted to copy and distribute verbatim or modified
+ copies of this license document, and changing it is allowed as long
+ as the name is changed.
+
+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. You just DO WHAT THE FUCK YOU WANT TO.

logrotee.cpp

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+#include <iostream>
+#include <string>
+#include <getopt.h>
+
+#pragma ide diagnostic ignored "ClangTidyInspection"
+
+using std::string;
+
+const char *programName = "0.1";
+const char *programVersion = "0.1";
+
+
+struct Arguments {
+	bool invalid;
+	string logFilePath;
+	string compressCommand;
+	string compressSuffix;
+	bool nullStdout;
+	size_t chunkSize;
+	bool dates;
+	ssize_t maxFiles;
+
+	bool isInvalid() const {
+		return invalid || logFilePath.empty();
+	}
+} commandArgs;
+
+void usage() {
+	std::cout << "Example usage: verbosecommand | logrotee /var/log/verbosecommand.log"
+			" --compress \"bzip2 {}\" --compress-suffix .bz2"
+			" --null --chunk 2M" << std::endl;
+}
+
+
+int main(int argc, char *argv[])
+{
+	int getoptResult;
+
+	for(;;) {
+		int optionIndex = 0;
+		static struct option longOptions[] = {
+				{"compress", required_argument, nullptr, 'c' },
+				{"compress-suffix", required_argument, nullptr, 's' },
+				{"null", no_argument, nullptr, 'n' },
+				{"dates", no_argument, nullptr, 'd' },
+				{"max-files", required_argument, nullptr, 'm'},
+				{"help", no_argument, nullptr, 'h' },
+				{"version", no_argument, nullptr, 'v' },
+				{nullptr, 0, nullptr, 0 }
+		};
+
+		getoptResult = getopt_long(argc, argv, "", longOptions, &optionIndex);
+		if (getoptResult == -1)
+			break;
+
+		switch (getoptResult) {
+			case 'c':
+				commandArgs.compressCommand = optarg;
+				break;
+
+			case 's':
+				commandArgs.compressSuffix = optarg;
+				break;
+
+			case 'n':
+				commandArgs.nullStdout = true;
+				break;
+
+			case 'd':
+				commandArgs.dates = true;
+				break;
+
+			case 'm':
+				try {
+					commandArgs.maxFiles = std::stoi(optarg);
+				}
+				catch (const std::logic_error& e) {
+					std::cout << "Cannot parse number: " << optarg << std::endl;
+					exit(1);
+				}
+				break;
+
+			case 'h':
+				usage();
+				exit(0);
+
+			case 'v':
+				std::cout << programName << " " << programVersion << std::endl;
+				exit(0);
+
+			default:
+				printf("?? getopt returned character code 0%o ??\n", getoptResult);
+		}
+	}
+
+	if (optind < argc) {
+		commandArgs.logFilePath = argv[optind];
+		optind++;
+		while (optind < argc) {
+			commandArgs.invalid = true;
+			std::cerr << "Extra command line argument:" << argv[optind] << std::endl;
+		}
+	}
+
+	if (commandArgs.isInvalid()) {
+		usage();
+		exit(1);
+	}
+
+
+
+	return 0;
+}

readme.md

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+What is it?
+===========
+
+A kind of `tee` that writes stdin to a rotated log file(s).
+
+EXAMPLES
+========
+
+    verbosecommand | logrotee /var/log/verbosecommand.log \
+    > /dev/null
+or
+
+    verbosecommand | logrotee /var/log/verbosecommand.log \
+      --compress "bzip2 {}" --compress-suffix .bz2 \
+      --null --chunk 2M
+
+If the output chunk file + <suffix> already exists, add an unique sequential suffix, currently `.1`, `.2`, `.3`, you get the idea.
+
+USAGE
+=====
+`logrotee <name> [-z|--compress <compress-command>] [-s|--compress-suffix <suffix>] [-n|--null] [--chunk|-k <size>]`
+
+`<name>`: Chunk file name. If the file exists, will be appended a number, like: `/var/log/verbosecommand.log.1`, `/var/log/verbosecommand.log.2`, and so on.
+If `--compress-suffix "bz2"` is given, will check for `/var/log/verbosecommand.log.bz2`, `/var/log/verbosecommand.log.1.bz2` and so on.
+
+`-z`, `--compress` `<compress-command>`	    Optional parameter - command to run on a complete chunk file. {} is substituted with a full file path.
+`-s`, `--compress-suffix` `<suffix>`	    File suffix to append to check for <name> existence, if
+`-n`, `--null`      Don't print the file to stdout.
+
+Planned:
+=======
+`-d`, `--dates`  Use dates instead of sequential numbers for rotation suffix.
+`-m`, `--max-files` `<amount>`     Maximum amount of rotated files. Delete the oldest chunk files when over this limit.
+Does not check if the files were not created by this instance of `logrotee`.