start on a more complex example

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 124 insertions, 0 deletions

diff --git a/doc/examples/daemon-depedencies/init.c b/doc/examples/daemon-depedencies/init.c
new file mode 100644
index 0000000..09a6abf
--- /dev/null
+++ b/doc/examples/daemon-depedencies/init.c
@@ -0,0 +1,124 @@
+#include <bus.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#define t(stmt)  if (stmt) goto fail
+
+
+static char msg[BUS_MEMORY_SIZE];
+static int argc;
+static char **argv;
+static char arg[4098];
+
+
+static void start_daemons()
+{
+	int i;
+	for (i = 1; i < argc; i++)
+		if (fork() == 0)
+			execl("./start-daemon", "./start-daemon", argv[i], NULL); 
+}
+
+
+static int callback(const char *message, void *user_data)
+{
+	pid_t pid;
+	char *arg2;
+	char *arg3;
+	if (!message) {
+		pid = fork();
+		t(pid == -1);
+		if (pid == 0) {
+			if (fork() == 0) {
+				start_daemons();
+			}
+			exit(0);
+		} else {
+			(void) waitpid(pid, NULL, 0); /* Let's pretend everything will go swimmingly. */
+		}
+		return 1;
+	}
+
+	strncpy(msg, message, BUS_MEMORY_SIZE - 1);
+	msg[BUS_MEMORY_SIZE - 1] = 0;
+
+	pid = fork();
+	t(pid == -1);
+
+	if (pid == 0) {
+		if (fork() == 0) {
+			arg2 = strchr(msg, ' ');
+			if (arg2 == NULL)
+				exit(0);
+			arg3 = strchr(++arg2, ' ');
+			if (arg3 == NULL)
+				exit(0);
+			*arg3++ = 0;
+			if (!strcmp(arg2, "require")) {
+				execl("./start-daemon", "./start-daemon", arg3, NULL);
+			} else if (!strcmp(arg2, "awaiting-started")) {
+				execl("./test-daemon", "./test-daemon", arg3, "started", NULL);
+			} else if (!strcmp(arg2, "awaiting-ready") || !strcmp(arg2, "awaiting")) {
+				execl("./test-daemon", "./test-daemon", arg3, "ready", NULL);
+			} else if (!strcmp(arg2, "started")) {
+				sprintf(arg,
+					"grep '^%s\\$' < \"${XDG_RUNTIME_DIR}/started-daemons\" >/dev/null || "
+					"echo %s >> \"${XDG_RUNTIME_DIR}/started-daemons\"",
+					arg3, arg3);
+				execlp("sh", "sh", "-c", arg, NULL);
+			} else if (!strcmp(arg2, "ready")) {
+				sprintf(arg,
+					"grep '^%s\\$' < \"${XDG_RUNTIME_DIR}/ready-daemons\" >/dev/null || "
+					"echo %s >> \"${XDG_RUNTIME_DIR}/ready-daemons\"",
+					arg3, arg3);
+				execlp("sh", "sh", "-c", arg, NULL);
+			}
+		}
+		exit(0);
+	} else {
+		(void) waitpid(pid, NULL, 0); /* Let's pretend everything will go swimmingly. */
+	}
+
+	return 1;
+	(void) user_data;
+
+fail:
+	perror("init");
+	return -1;
+}
+
+
+int main(int argc_, char *argv_[])
+{
+	char *bus_address = NULL;
+	bus_t bus;
+	argv = argv_;
+	argc = argc_;
+	if (argc < 2) {
+		fprintf(stderr, "USAGE: %s daemon...\n", *argv);
+		return 1;
+	}
+	t(setenv("XDG_RUNTIME_DIR", "./run", 1));  /* Real init systems with not have the period. */
+	system("mkdir -p -- \"${XDG_RUNTIME_DIR}\"");
+	system("truncate -s 0 -- \"${XDG_RUNTIME_DIR}/started-daemons\"");
+	system("truncate -s 0 -- \"${XDG_RUNTIME_DIR}/ready-daemons\"");
+	t(bus_create(NULL, 1, &bus_address));
+	fprintf(stderr, "\033[00;01;31mexport BUS_INIT=%s\033[00m\n", bus_address);
+	fprintf(stderr, "\033[00;31mexport XDG_RUNTIME_DIR=./run\033[00m\n");
+	t(setenv("BUS_INIT", bus_address, 1));
+	t(bus_open(&bus, bus_address, BUS_RDONLY));
+	t(bus_read(&bus, callback, NULL));
+	bus_close(&bus);
+	free(bus_address);
+	return 0;
+
+fail:
+	perror("init");
+	bus_close(&bus);
+	free(bus_address);
+	return 1;
+}
+