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-rw-r--r--toys/pending/dmesg.c168
1 files changed, 80 insertions, 88 deletions
diff --git a/toys/pending/dmesg.c b/toys/pending/dmesg.c
index 198f64a1..b9156562 100644
--- a/toys/pending/dmesg.c
+++ b/toys/pending/dmesg.c
@@ -2,10 +2,13 @@
*
* Copyright 2006, 2007 Rob Landley <rob@landley.net>
*
- * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/dmesg.html
+ * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/dmesg.html
+ *
+ * Don't ask me why the horrible new dmesg API is still in "testing":
+ * http://kernel.org/doc/Documentation/ABI/testing/dev-kmsg
// We care that FLAG_c is 1, so keep c at the end.
-USE_DMESG(NEWTOY(dmesg, "w(follow)CSTtrs#<1n#c[!Ttr][!Cc]", TOYFLAG_BIN))
+USE_DMESG(NEWTOY(dmesg, "w(follow)CSTtrs#<1n#c[!Ttr][!Cc][!Sw]", TOYFLAG_BIN))
config DMESG
bool "dmesg"
@@ -35,7 +38,7 @@ GLOBALS(
long size;
int use_color;
- struct sysinfo info;
+ time_t tea;
)
static void color(int c)
@@ -43,50 +46,44 @@ static void color(int c)
if (TT.use_color) printf("\033[%dm", c);
}
-static void format_message(char *msg, int new) {
- unsigned long long time_s;
- unsigned long long time_us;
+static void format_message(char *msg, int new)
+{
+ unsigned long long time_s, time_us;
int facpri, subsystem, pos;
char *p, *text;
// The new /dev/kmsg and the old syslog(2) formats differ slightly.
if (new) {
- if (sscanf(msg, "%u,%*u,%llu,%*[^;];%n", &facpri, &time_us, &pos) != 2)
+ if (sscanf(msg, "%u,%*u,%llu,%*[^;]; %n", &facpri, &time_us, &pos) != 2)
return;
time_s = time_us/1000000;
time_us %= 1000000;
- } else {
- if (sscanf(msg, "<%u>[%llu.%llu] %n",
- &facpri, &time_s, &time_us, &pos) != 3)
- return;
- }
+ } else if (sscanf(msg, "<%u>[%llu.%llu] %n",
+ &facpri, &time_s, &time_us, &pos) != 3) return;
// Drop extras after end of message text.
- text = msg + pos;
- if ((p = strchr(text, '\n'))) *p = 0;
+ if ((p = strchr(text = msg+pos, '\n'))) *p = 0;
// Is there a subsystem? (The ": " is just a convention.)
p = strstr(text, ": ");
- subsystem = p ? (p - text) : 0;
+ subsystem = p ? (p-text) : 0;
- // "Raw" is a lie for /dev/kmsg. In practice, it just means we show the
- // syslog facility/priority at the start of each line to emulate the
- // historical syslog(2) format.
- if (toys.optflags&FLAG_r) printf("<%d>", facpri);
+ // To get "raw" output for /dev/kmsg we need to add priority to each line
+ if (toys.optflags&FLAG_r) {
+ color(0);
+ printf("<%d>", facpri);
+ }
// Format the time.
if (!(toys.optflags&FLAG_t)) {
color(32);
if (toys.optflags&FLAG_T) {
- time_t t = (time(NULL) - TT.info.uptime) + time_s;
+ time_t t = TT.tea+time_s;
char *ts = ctime(&t);
- printf("[%.*s] ", (int)(strlen(ts) - 1), ts);
- } else {
- printf("[%5lld.%06lld] ", time_s, time_us);
- }
- color(0);
+ printf("[%.*s] ", (int)(strlen(ts)-1), ts);
+ } else printf("[%5lld.%06lld] ", time_s, time_us);
}
// Errors (or worse) are shown in red, subsystems are shown in yellow.
@@ -94,15 +91,9 @@ static void format_message(char *msg, int new) {
color(33);
printf("%.*s", subsystem, text);
text += subsystem;
- color(0);
- }
- if (!((facpri&7) <= 3)) xputs(text);
- else {
- color(31);
- printf("%s", text);
- color(0);
- xputc('\n');
}
+ color(31*((facpri&7)<=3));
+ xputs(text);
}
static int xklogctl(int type, char *buf, int len)
@@ -114,74 +105,75 @@ static int xklogctl(int type, char *buf, int len)
return rc;
}
-// Use klogctl for reading if we're on a pre-3.5 kernel.
-static void legacy_mode()
+static void dmesg_cleanup(void)
{
- char *data, *to, *from;
- int size;
-
- // Figure out how much data we need, and fetch it.
- if (!(size = TT.size)) size = xklogctl(10, 0, 0);
- data = to = from = xmalloc(size+1);
- data[size = xklogctl(3 + (toys.optflags & FLAG_c), data, size)] = 0;
-
- // Break into messages (one per line) and send each one to format_message.
- to = data + size;
- while (from < to) {
- char *msg_end = memchr(from, '\n', (to-from));
-
- if (!msg_end) break;
- *msg_end = '\0';
- format_message(from, 0);
- from = msg_end + 1;
- }
-
- if (CFG_TOYBOX_FREE) free(data);
+ color(0);
}
-static void print_all(void)
+void dmesg_main(void)
{
- if (toys.optflags&FLAG_T) sysinfo(&TT.info);
- if (toys.optflags&FLAG_S) return legacy_mode();
+ TT.use_color = isatty(1);
- // http://kernel.org/doc/Documentation/ABI/testing/dev-kmsg
+ if (TT.use_color) sigatexit(dmesg_cleanup);
+ // If we're displaying output, is it klogctl or /dev/kmsg?
+ if (toys.optflags & (FLAG_C|FLAG_n)) goto no_output;
- // Each read returns one message. By default, we block when there are no
- // more messages (--follow); O_NONBLOCK is needed for for usual behavior.
- int fd = xopen("/dev/kmsg", O_RDONLY | ((toys.optflags&FLAG_w)?0:O_NONBLOCK));
+ if (toys.optflags&FLAG_T) {
+ struct sysinfo info;
- // With /dev/kmsg, SYSLOG_ACTION_CLEAR (5) doesn't actually remove anything;
- // you need to seek to the last clear point.
- lseek(fd, 0, SEEK_DATA);
+ sysinfo(&info);
+ TT.tea = time(0)-info.uptime;
+ }
- while (1) {
- char msg[8192]; // CONSOLE_EXT_LOG_MAX.
+ if (!(toys.optflags&FLAG_S)) {
+ char msg[8193]; // CONSOLE_EXT_LOG_MAX+1
ssize_t len;
-
- // kmsg fails with EPIPE if we try to read while the buffer moves under
- // us; the next read will succeed and return the next available entry.
- do {
- len = read(fd, msg, sizeof(msg));
- } while (len == -1 && errno == EPIPE);
- // All reads from kmsg fail if you're on a pre-3.5 kernel.
- if (len == -1 && errno == EINVAL) {
- close(fd);
- return legacy_mode();
+ int fd;
+
+ // Each read returns one message. By default, we block when there are no
+ // more messages (--follow); O_NONBLOCK is needed for for usual behavior.
+ fd = open("/dev/kmsg", O_RDONLY|(O_NONBLOCK*!(toys.optflags&FLAG_w)));
+ if (fd == -1) goto klogctl_mode;
+
+ // SYSLOG_ACTION_CLEAR(5) doesn't actually remove anything from /dev/kmsg,
+ // you need to seek to the last clear point.
+ lseek(fd, 0, SEEK_DATA);
+
+ for (;;) {
+ // why does /dev/kmesg return EPIPE instead of EAGAIN if oldest message
+ // expires as we read it?
+ if (-1==(len = read(fd, msg, sizeof(msg))) && errno==EPIPE) continue;
+ // read() from kmsg always fails on a pre-3.5 kernel.
+ if (len==-1 && errno==EINVAL) goto klogctl_mode;
+ if (len<1) break;
+
+ msg[len] = 0;
+ format_message(msg, 1);
+ }
+ close(fd);
+ } else {
+ char *data, *to, *from, *end;
+ int size;
+
+klogctl_mode:
+ // Figure out how much data we need, and fetch it.
+ if (!(size = TT.size)) size = xklogctl(10, 0, 0);
+ data = from = xmalloc(size+1);
+ data[size = xklogctl(3+(toys.optflags&FLAG_c), data, size)] = 0;
+
+ // Send each line to format_message.
+ to = data + size;
+ while (from < to) {
+ if (!(end = memchr(from, '\n', to-from))) break;
+ *end = 0;
+ format_message(from, 0);
+ from = end + 1;
}
- if (len <= 0) break;
- msg[len] = 0;
- format_message(msg, 1);
+ if (CFG_TOYBOX_FREE) free(data);
}
- close(fd);
-}
-
-void dmesg_main(void)
-{
- TT.use_color = isatty(1);
-
- if (!(toys.optflags & (FLAG_C|FLAG_n))) print_all();
+no_output:
// Set the log level?
if (toys.optflags & FLAG_n) xklogctl(8, 0, TT.level);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 05:56:41 +0000