X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=sysklogd%2Flogread.c;h=ae0b2194b80b0b6cf33175a63608344eaa7dddeb;hb=5bc8c005a8e15c43285bc595a8d404de67a482ac;hp=6567df374fd7e9c4fefe3cc33f801c2fdf9084dc;hpb=9b49a5ed8551e46892af3f676e5d96d21b540e3c;p=oweals%2Fbusybox.git

diff --git a/sysklogd/logread.c b/sysklogd/logread.c
index 6567df374..ae0b2194b 100644
--- a/sysklogd/logread.c
+++ b/sysklogd/logread.c
@@ -6,9 +6,16 @@
  *
  * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
+//usage:#define logread_trivial_usage
+//usage:       "[-f]"
+//usage:#define logread_full_usage "\n\n"
+//usage:       "Show messages in syslogd's circular buffer\n"
+//usage:     "\nOptions:"
+//usage:     "\n	-f	Output data as log grows"
+
 #include "libbb.h"
 #include <sys/ipc.h>
 #include <sys/sem.h>
@@ -16,20 +23,34 @@
 
 #define DEBUG 0
 
+/* our shared key (syslogd.c and logread.c must be in sync) */
 enum { KEY_ID = 0x414e4547 }; /* "GENA" */
 
-static struct shbuf_ds {
+struct shbuf_ds {
 	int32_t size;           // size of data - 1
 	int32_t tail;           // end of message list
 	char data[1];           // messages
-} *shbuf;
-
-// Semaphore operation structures
-static struct sembuf SMrup[1] = {{0, -1, IPC_NOWAIT | SEM_UNDO}}; // set SMrup
-static struct sembuf SMrdn[2] = {{1, 0}, {0, +1, SEM_UNDO}}; // set SMrdn
-
-
-static void error_exit(const char *str) ATTRIBUTE_NORETURN;
+};
+
+static const struct sembuf init_sem[3] = {
+	{0, -1, IPC_NOWAIT | SEM_UNDO},
+	{1, 0}, {0, +1, SEM_UNDO}
+};
+
+struct globals {
+	struct sembuf SMrup[1]; // {0, -1, IPC_NOWAIT | SEM_UNDO},
+	struct sembuf SMrdn[2]; // {1, 0}, {0, +1, SEM_UNDO}
+	struct shbuf_ds *shbuf;
+} FIX_ALIASING;
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define SMrup (G.SMrup)
+#define SMrdn (G.SMrdn)
+#define shbuf (G.shbuf)
+#define INIT_G() do { \
+	memcpy(SMrup, init_sem, sizeof(init_sem)); \
+} while (0)
+
+static void error_exit(const char *str) NORETURN;
 static void error_exit(const char *str)
 {
 	//release all acquired resources
@@ -46,21 +67,23 @@ static void sem_up(int semid)
 		error_exit("semop[SMrup]");
 }
 
-static void interrupted(int sig ATTRIBUTE_UNUSED)
+static void interrupted(int sig UNUSED_PARAM)
 {
 	signal(SIGINT, SIG_IGN);
 	shmdt(shbuf);
-	exit(0);
+	exit(EXIT_SUCCESS);
 }
 
 int logread_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int logread_main(int argc, char **argv)
+int logread_main(int argc UNUSED_PARAM, char **argv)
 {
-	int cur;
+	unsigned cur;
 	int log_semid; /* ipc semaphore id */
 	int log_shmid; /* ipc shared memory id */
 	smallint follow = getopt32(argv, "f");
 
+	INIT_G();
+
 	log_shmid = shmget(KEY_ID, 0, 0);
 	if (log_shmid == -1)
 		bb_perror_msg_and_die("can't find syslogd buffer");
@@ -119,7 +142,7 @@ int logread_main(int argc, char **argv)
 		} else { /* logread -f */
 			if (cur == shbuf_tail) {
 				sem_up(log_semid);
-				fflush(stdout);
+				fflush_all();
 				sleep(1); /* TODO: replace me with a sleep_on */
 				continue;
 			}