--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dep/animia/src/linux.cpp	Thu Sep 28 12:35:21 2023 -0400
@@ -0,0 +1,109 @@
+#include <string>
+#include <vector>
+#include <fstream>
+#include <filesystem>
+#include <unordered_map>
+#include <iostream>
+#include <sstream>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <algorithm>
+
+#define PROC_LOCATION "/proc"
+
+namespace Animia::Linux {
+
+std::vector<int> get_all_pids() {
+	std::vector<int> ret;
+	for (const auto& dir : std::filesystem::directory_iterator(PROC_LOCATION)) {
+		int pid;
+		try {
+			pid = std::stoi(dir.path().stem());
+		} catch (std::invalid_argument) {
+			continue;
+		}
+		ret.push_back(pid);
+	}
+	return ret;
+}
+
+std::string get_process_name(int pid) {
+	std::string path = PROC_LOCATION "/" + std::to_string(pid) + "/comm";
+	std::ifstream t(path);
+	std::stringstream buf;
+	buf << t.rdbuf();
+	std::string str = buf.str();
+	str.erase(std::remove(str.begin(), str.end(), '\n'), str.end());
+	return str;
+}
+
+static bool is_regular_file(std::string link) {
+	struct stat sb;
+	if (stat(link.c_str(), &sb) == -1)
+		return false;
+	return S_ISREG(sb.st_mode);
+}
+
+static bool are_flags_ok(int pid, int fd) {
+	std::string path = PROC_LOCATION "/" + std::to_string(pid) + "/fdinfo/" + std::to_string(fd);
+	std::ifstream t(path);
+	std::stringstream buffer;
+	buffer << t.rdbuf();
+	std::string raw;
+	int flags = 0;
+	while (std::getline(buffer, raw)) {
+		if (raw.rfind("flags:", 0) == 0) {
+			flags = std::stoi(raw.substr(raw.find_last_not_of("0123456789") + 1));
+		}
+	}
+	if (flags & O_WRONLY || flags & O_RDWR)
+		return false;
+	return true;
+}
+
+static int get_size_of_link(std::string link) {
+	struct stat sb;
+	if (lstat(link.c_str(), &sb) == -1)
+		return -1;
+	return sb.st_size + 1;
+}
+
+std::vector<std::string> get_open_files(int pid) {
+	std::vector<std::string> ret;
+	std::string path = PROC_LOCATION "/" + std::to_string(pid) + "/fd";
+	try {
+		for (const auto& dir : std::filesystem::directory_iterator(path)) {
+			if (!are_flags_ok(pid, std::stoi(dir.path().stem())))
+				continue;
+			/* get filename size */
+			int size = get_size_of_link(dir.path().string());
+			/* allocate buffer */
+			char* buf = (char*)calloc(size, sizeof(char));
+			//std::string buf('\0', size);
+			/* read filename to buffer */
+			int r = readlink(dir.path().c_str(), buf, size);
+
+			if (r < 0)
+				continue;
+			if (!is_regular_file(buf))
+				continue;
+			ret.push_back(buf);
+			free(buf);
+		}
+	} catch (std::filesystem::filesystem_error const& ex) {
+		if (ex.code().value() != 13) // 13 == permissions error, common with /proc, ignore
+			throw;
+	}
+	return ret;
+}
+
+std::unordered_map<int, std::vector<std::string>> get_all_open_files() {
+	std::unordered_map<int, std::vector<std::string>> map;
+	std::vector<int> pids = get_all_pids();
+	for (int i: pids)
+		map[i] = get_open_files(i);
+	return map;
+}
+
+}