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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-01-10 22:35:54 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-01-10 22:35:54 +0000
commit085231fbbad159d2275cbd5ecdcf4732512bb80f (patch)
tree30b03f19951317b9ff8a3eda5b7b5c13d217969a /sysklogd
parent1a8bf7f5d39c854bcbd3af6667c5ad4b2de3ff2c (diff)
downloadbusybox-085231fbbad159d2275cbd5ecdcf4732512bb80f.tar.gz
busybox-085231fbbad159d2275cbd5ecdcf4732512bb80f.tar.bz2
code shrinkage by Bernhard Fischer <rep.nop@aon.at>
Diffstat (limited to 'sysklogd')
-rw-r--r--sysklogd/logread.c80
1 files changed, 31 insertions, 49 deletions
diff --git a/sysklogd/logread.c b/sysklogd/logread.c
index 4427cf37e..d092056bf 100644
--- a/sysklogd/logread.c
+++ b/sysklogd/logread.c
@@ -11,37 +11,30 @@
#include "busybox.h"
#include <sys/ipc.h>
-//#include <sys/types.h>
#include <sys/sem.h>
#include <sys/shm.h>
-//#include <signal.h>
-//#include <setjmp.h>
#define DEBUG 0
-static const long KEY_ID = 0x414e4547; /* "GENA" */
+enum { KEY_ID = 0x414e4547 }; /* "GENA" */
static struct shbuf_ds {
- int32_t size; // size of data written
- int32_t head; // start of message list
- int32_t tail; // end of message list
- char data[1]; // data/messages
-} *buf; // shared memory pointer
-
+ int32_t size; // size of data written
+ int32_t head; // start of message list
+ int32_t tail; // end of message list
+ char data[1]; // data/messages
+} *buf; // shared memory pointer
// 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 int log_shmid = -1; // ipc shared memory id
-static int log_semid = -1; // ipc semaphore id
static void error_exit(const char *str) ATTRIBUTE_NORETURN;
static void error_exit(const char *str)
{
//release all acquired resources
- if (log_shmid != -1)
- shmdt(buf);
+ shmdt(buf);
bb_perror_msg_and_die(str);
}
@@ -54,16 +47,7 @@ static void sem_up(int semid)
error_exit("semop[SMrup]");
}
-/*
- * sem_down - down()'s a semaphore
- */
-static void sem_down(int semid)
-{
- if (semop(semid, SMrdn, 2) == -1)
- error_exit("semop[SMrdn]");
-}
-
-static void interrupted(int sig)
+static void interrupted(int sig ATTRIBUTE_UNUSED)
{
signal(SIGINT, SIG_IGN);
shmdt(buf);
@@ -73,23 +57,18 @@ static void interrupted(int sig)
int logread_main(int argc, char **argv)
{
int cur;
- int follow = 1;
-
- if (argc != 2 || argv[1][0]!='-' || argv[1][1]!='f' ) {
- follow = 0;
- /* no options, no getopt */
- if (argc > 1)
- bb_show_usage();
- }
+ int log_semid; /* ipc semaphore id */
+ int log_shmid; /* ipc shared memory id */
+ smallint follow = getopt32(argc, argv, "f");
log_shmid = shmget(KEY_ID, 0, 0);
if (log_shmid == -1)
- error_exit("can't find circular buffer");
+ bb_perror_msg_and_die("can't find syslogd buffer");
// Attach shared memory to our char*
buf = shmat(log_shmid, NULL, SHM_RDONLY);
if (buf == NULL)
- error_exit("can't get access to syslogd buffer");
+ bb_perror_msg_and_die("can't access syslogd buffer");
log_semid = semget(KEY_ID, 0, 0);
if (log_semid == -1)
@@ -102,38 +81,42 @@ int logread_main(int argc, char **argv)
cur = follow ? buf->tail : buf->head;
do {
-#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING
+#if ENABLE_FEATURE_LOGREAD_REDUCED_LOCKING
char *buf_data;
int log_len, j;
#endif
- sem_down(log_semid);
+ if (semop(log_semid, SMrdn, 2) == -1)
+ error_exit("semop[SMrdn]");
if (DEBUG)
- printf("head:%i cur:%d tail:%i size:%i\n", buf->head, cur, buf->tail, buf->size);
+ printf("head:%i cur:%d tail:%i size:%i\n",
+ buf->head, cur, buf->tail, buf->size);
if (buf->head == buf->tail || cur == buf->tail) {
if (follow) {
sem_up(log_semid);
- sleep(1); /* TODO: replace me with a sleep_on */
+ fflush(stdout);
+ sleep(1); /* TODO: replace me with a sleep_on */
continue;
- } else {
- printf("<empty syslog>\n");
}
+ puts("<empty syslog>");
}
// Read Memory
-#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING
+#if ENABLE_FEATURE_LOGREAD_REDUCED_LOCKING
log_len = buf->tail - cur;
if (log_len < 0)
log_len += buf->size;
buf_data = xmalloc(log_len);
- if (buf->tail >= cur) {
- memcpy(buf_data, buf->data + cur, log_len);
- } else {
- memcpy(buf_data, buf->data + cur, buf->size - cur);
+ if (buf->tail >= cur)
+ j = log_len;
+ else
+ j = buf->size - cur;
+ memcpy(buf_data, buf->data + cur, j);
+
+ if (buf->tail < cur)
memcpy(buf_data + buf->size - cur, buf->data, buf->tail);
- }
cur = buf->tail;
#else
while (cur != buf->tail) {
@@ -146,16 +129,15 @@ int logread_main(int argc, char **argv)
// release the lock on the log chain
sem_up(log_semid);
-#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING
+#if ENABLE_FEATURE_LOGREAD_REDUCED_LOCKING
for (j = 0; j < log_len; j += strlen(buf_data+j) + 1) {
fputs(buf_data + j, stdout);
}
free(buf_data);
#endif
- fflush(stdout);
} while (follow);
shmdt(buf);
- return EXIT_SUCCESS;
+ fflush_stdout_and_exit(EXIT_SUCCESS);
}