1 files changed, 120 insertions, 0 deletions
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..d597629
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,120 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <optional>
+#include <utility>
+#include <cstring>
+#include "xutil.h"
+#include "keysym_table.h"
+
+
+namespace {
+	void usage(const char *argv0) {
+		std::cerr
+			<< "Usage:\n"
+			<< "  " << argv0 << " <key>\n"
+			<< "  " << argv0 << " [<key> <output>]*\n"
+			<< "\n"
+			<< "Keys are specified with the X11 keysym name or ID (in hexadecimal with \"0x\").\n"
+			<< "Both are given by xev(1).\n"
+			<< "Examples:\n"
+			<< "- KP_1 and 0xffb1 are valid key values for the '1' key on the numpad.\n"
+			<< "- XF86Launch7 and 0x1008ff47 are valid key values for F16 on an Apple keyboard.\n"
+			<< "The values can also be found in /usr/include/xkbcommon/xkbcommon-keysyms.h .\n"
+			<< "\n"
+			<< "If a single key is given, the program grabs that key and exits when the key is\n"
+			<< "pressed. If multiple keys are given, the output string corresponding to the\n"
+			<< "pressed key will be printed before exiting.\n"
+			;
+	}
+
+	std::vector<std::pair<x::Keysym, std::string>> parse_watchlist(int argc, char **argv) {
+		std::vector<std::pair<x::Keysym, std::string>> watchlist;
+
+		if (argc <= 1) {
+			usage(argv[0]);
+			exit(1);
+		}
+
+		for (int i = 1; i < argc; i++) {
+			if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
+				usage(argv[0]);
+				exit(0);
+			}
+
+			std::optional<x::Keysym> msym;
+
+			if (argv[i][0] == '0' && argv[i][1] == 'x') {
+				char *endp;
+				unsigned code = strtol(argv[i] + 2, &endp, 16);
+				if (argv[i][2] == '\0' || *endp != '\0') {
+					std::cerr << "Invalid hexadecimal number in '" << argv[i] << "'\n";
+					exit(1);
+				}
+				msym = x::Keysym{code};
+			}
+
+			if (!msym) {
+				for (size_t j = 0; j < keysym_table.size(); j++) {
+					if (strcmp(argv[i], keysym_table[j].first) == 0) {
+						msym = keysym_table[j].second;
+						break;
+					}
+				}
+			}
+
+			if (!msym) {
+				std::cerr << "Unknown keysym '" << argv[i] << "'\n";
+				exit(1);
+			}
+
+			std::string output;
+			if (i == 1 && argc == 2) {
+				// empty output
+			} else if (i >= argc - 1) {
+				std::cerr << "Missing output for keysym '" << argv[i] << "'\n";
+				exit(1);
+			} else {
+				output = argv[i+1];
+				i++;  // skip output
+			}
+
+			watchlist.emplace_back(*msym, std::move(output));
+		}
+
+		return watchlist;
+	}
+}
+
+int main(int argc, char **argv) {
+	std::vector<std::pair<x::Keysym, std::string>> watchlist = parse_watchlist(argc, argv);
+
+	auto dpypair = x::XOpenDisplayRAII(nullptr);
+	Display *dpy = dpypair.first;
+
+	Window root = DefaultRootWindow(dpy);
+
+	std::vector<x::UponExit<std::function<void()>>> cleaners;
+	cleaners.reserve(watchlist.size());
+	std::vector<x::Keycode> keycodes;
+	keycodes.reserve(watchlist.size());
+
+	for (const auto &p : watchlist) {
+		x::Keycode code = p.first.toCode(dpy);
+		keycodes.push_back(code);
+		cleaners.push_back(x::XGrabKeyRAII(dpy, code, AnyModifier, root));
+	}
+
+	XSelectInput(dpy, root, KeyPressMask);
+	while (true) {
+		XEvent ev;
+		XNextEvent(dpy, &ev);
+		if (ev.type != KeyPress) continue;
+		for (size_t i = 0; i < watchlist.size(); i++) {
+			if (ev.xkey.keycode == (unsigned int)keycodes[i]) {
+				if (watchlist[i].second.size() > 0) std::cout << watchlist[i].second << std::endl;
+				return 0;
+			}
+		}
+	}
+}