Initial commit.

main.c

@@ -0,0 +1,208 @@
+#include <X11/Xlib.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#define len(arr) (sizeof(arr) / sizeof(arr[0]))
+
+typedef struct {
+	char *command;
+	unsigned int interval;
+	unsigned int signal;
+} Block;
+#include "config.h"
+
+void getCommand(const Block *, char *);
+void getCommands(int);
+int getStatus(char *, char *);
+void setRoot();
+void debug();
+void statusLoop();
+void termHandler(int);
+void signalHandler(int num);
+void buttonHandler(int sig, siginfo_t *si, void *ucontext);
+void getSignalCommands(int signal);
+void setupSignals();
+void signalHandler(int signum);
+void sleepMillis(unsigned long);
+
+static Display *dpy;
+static int screen;
+static Window root;
+static char commands[len(blocks)][256];
+static char statusbar[len(blocks)][CMDLENGTH];
+static char statusStr[2][len(blocks) * CMDLENGTH +
+			 (len(delimiter) - 1) * (len(blocks) - 1) + 1];
+static int statusContinue = 1;
+static void (*writestatus)() = setRoot;
+
+void replace(char *str, char old, char new) {
+	int i = 0;
+	while (str[i] != '\0') {
+		if (str[i] == old) {
+			str[i] = new;
+			return;
+		}
+		i++;
+	}
+}
+
+void getSignalCommands(int signal) {
+	const Block *current;
+	for (int i = 0; i < len(blocks); i++) {
+		current = blocks + i;
+		if (current->signal == signal)
+			getCommand(current, statusbar[i]);
+	}
+}
+
+void setupSignals() {
+	struct sigaction sa;
+
+	// Handle block update signals
+	for (int i = 0; i < len(blocks); i++) {
+		if (blocks[i].signal > 0) {
+			signal(SIGRTMIN + blocks[i].signal, signalHandler);
+			sigaddset(&sa.sa_mask, SIGRTMIN + blocks[i].signal);
+		}
+	}
+
+	// Handle mouse events
+	sa.sa_sigaction = buttonHandler;
+	sa.sa_flags = SA_SIGINFO;
+	sigaction(SIGUSR1, &sa, NULL);
+	struct sigaction sigchld_action = {
+	    .sa_handler = SIG_DFL,
+	    .sa_flags = SA_NOCLDWAIT,
+	};
+	sigaction(SIGCHLD, &sigchld_action, NULL);
+}
+
+// Open process *command and store output in *output
+void getCommand(const Block *block, char *output) {
+	// Leave signal in output for dwm
+	if (block->signal) {
+		output[0] = block->signal;
+		output++;
+	}
+
+	char *cmd = block->command;
+	FILE *cmdFile = popen(cmd, "r");
+	if (!cmdFile) return;
+
+	int fd = fileno(cmdFile);
+	if (!read(fd, output, CMDLENGTH - 2))
+		output[0] = '\0';
+	else {
+		output[CMDLENGTH - 2] = '\0';
+		replace(output, '\n', '\0');
+	}
+	pclose(cmdFile);
+}
+
+void getCommands(int time) {
+	const Block *current;
+	for (int i = 0; i < len(blocks); i++) {
+		current = blocks + i;
+		if ((current->interval != 0 && time % current->interval == 0) ||
+		    time == -1)
+			getCommand(current, statusbar[i]);
+	}
+}
+
+int getStatus(char *new, char *old) {
+	strcpy(old, new);
+	new[0] = '\0';
+	for (int i = 0; i < len(blocks); i++) {
+		strcat(new, statusbar[i]);
+		if (strlen(statusbar[i]) > (blocks[i].signal != 0) &&
+		    i != len(blocks) - 1)
+			strcat(new, delimiter);
+	}
+	new[strlen(new)] = '\0';
+	return strcmp(new, old);
+}
+
+void setRoot() {
+	// Only set root if text has changed.
+	if (!getStatus(statusStr[0], statusStr[1])) return;
+
+	Display *d = XOpenDisplay(NULL);
+	if (d) dpy = d;
+	screen = DefaultScreen(dpy);
+	root = RootWindow(dpy, screen);
+	XStoreName(dpy, root, statusStr[0]);
+	XCloseDisplay(dpy);
+}
+
+void debug() {
+	// Only write out if text has changed
+	if (!getStatus(statusStr[0], statusStr[1])) return;
+
+	write(STDOUT_FILENO, statusStr[0], strlen(statusStr[0]));
+	write(STDOUT_FILENO, "\n", 1);
+}
+
+void statusLoop() {
+	setupSignals();
+	unsigned long int i = 0;
+	getCommands(-1);
+	while (statusContinue) {
+		getCommands(i);
+		writestatus();
+		sleep(1.0);
+		i++;
+	}
+}
+
+void signalHandler(int signum) {
+	getSignalCommands(signum - SIGRTMIN);
+	writestatus();
+}
+
+void buttonHandler(int sig, siginfo_t *si, void *ucontext) {
+	char button[2] = {'0' + si->si_value.sival_int & 0xff, '\0'};
+	sig = si->si_value.sival_int >> 8;
+	if (fork() == 0) {
+		const Block *current;
+		char *shCommand = NULL;
+		for (int i = 0; i < len(blocks); i++) {
+			current = blocks + i;
+			if (current->signal == sig) {
+				shCommand = commands[i];
+				break;
+			}
+		}
+
+		if (shCommand) {
+			char *command[] = {"/bin/sh", "-c", shCommand, NULL};
+			setenv("BLOCK_BUTTON", button, 1);
+			setsid();
+			execvp(command[0], command);
+		}
+		exit(EXIT_SUCCESS);
+	}
+}
+
+void termHandler(int sigNum) {
+	statusContinue = 0;
+	exit(0);
+}
+
+int main(int argc, char **argv) {
+	const int processID = getpid();
+	for (int i = 0; i < len(blocks); i++)
+		sprintf(commands[i], "%s && kill -%d %d", blocks[i].command,
+			SIGRTMIN + blocks[i].signal, processID);
+
+	for (int i = 0; i < argc; i++)
+		if (!strcmp("-d", argv[i])) writestatus = debug;
+
+	signal(SIGTERM, termHandler);
+	signal(SIGINT, termHandler);
+	statusLoop();
+}
+