Write to swaynag pipe fd directly on config errors

sway/swaynag.c

@@ -0,0 +1,103 @@
+#include <fcntl.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "log.h"
+#include "sway/swaynag.h"
+
+void swaynag_clone(struct swaynag_instance *dest,
+		struct swaynag_instance *src) {
+	dest->args = src->args;
+	dest->pid = src->pid;
+	dest->fd[0] = src->fd[0];
+	dest->fd[1] = src->fd[1];
+	dest->detailed = src->detailed;
+}
+
+bool swaynag_spawn(const char *swaynag_command,
+		struct swaynag_instance *swaynag) {
+	if (swaynag->detailed) {
+		if (pipe(swaynag->fd) != 0) {
+			wlr_log(WLR_ERROR, "Failed to create pipe for swaynag");
+			return false;
+		}
+		fcntl(swaynag->fd[1], F_SETFD, FD_CLOEXEC);
+	}
+
+	pid_t pid;
+	if ((pid = fork()) == 0) {
+		if (swaynag->detailed) {
+			close(swaynag->fd[1]);
+			dup2(swaynag->fd[0], STDIN_FILENO);
+			close(swaynag->fd[0]);
+		}
+
+		size_t length = strlen(swaynag_command) + strlen(swaynag->args) + 2;
+		char *cmd = malloc(length);
+		snprintf(cmd, length, "%s %s", swaynag_command, swaynag->args);
+		execl("/bin/sh", "/bin/sh", "-c", cmd, NULL);
+		_exit(0);
+	} else if (pid < 0) {
+		wlr_log(WLR_ERROR, "Failed to create fork for swaynag");
+		if (swaynag->detailed) {
+			close(swaynag->fd[0]);
+			close(swaynag->fd[1]);
+		}
+		return false;
+	}
+
+	if (swaynag->detailed) {
+		close(swaynag->fd[0]);
+	}
+	swaynag->pid = pid;
+	return true;
+}
+
+
+void swaynag_kill(struct swaynag_instance *swaynag) {
+	if (swaynag->pid > 0) {
+		kill(swaynag->pid, SIGTERM);
+		swaynag->pid = -1;
+	}
+}
+
+void swaynag_log(const char *swaynag_command, struct swaynag_instance *swaynag,
+		const char *fmt, ...) {
+	if (!swaynag->detailed) {
+		wlr_log(WLR_ERROR, "Attempting to write to non-detailed swaynag inst");
+		return;
+	}
+
+	if (swaynag->pid <= 0 && !swaynag_spawn(swaynag_command, swaynag)) {
+		return;
+	}
+
+	va_list args;
+	va_start(args, fmt);
+	size_t length = vsnprintf(NULL, 0, fmt, args) + 1;
+	va_end(args);
+
+	char *temp = malloc(length + 1);
+	if (!temp) {
+		wlr_log(WLR_ERROR, "Failed to allocate buffer for swaynag log entry.");
+		return;
+	}
+
+	va_start(args, fmt);
+	vsnprintf(temp, length, fmt, args);
+	va_end(args);
+
+	write(swaynag->fd[1], temp, length);
+
+	free(temp);
+}
+
+void swaynag_show(struct swaynag_instance *swaynag) {
+	if (swaynag->detailed && swaynag->pid > 0) {
+		close(swaynag->fd[1]);
+	}
+}
+