dmesg: add --decode to print readable facility and level

 # dmesg --decode
 ...
 kern  :info  : [53335.743185] PM: resume of devices complete after 2496.795 msecs
 kern  :debug : [53335.743593] PM: Finishing wakeup.
 kern  :warn  : [53335.743595] Restarting tasks ... done.
 kern  :info  : [53335.790452] video LNXVIDEO:00: Restoring backlight state
 kern  :debug : [53336.418576] e1000e 0000:00:19.0: irq 45 for MSI/MSI-X

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/dmesg.1 b/sys-utils/dmesg.1
index 9518ecb64b34664adae7e10bb0bfc933546ae03f..cd8f9cfe0f5f7956ad45a4072d0838114aa16d56 100644 (file)
--- a/sys-utils/dmesg.1
+++ b/sys-utils/dmesg.1
@@ -44,6 +44,8 @@ Restrict output to defined (comma separated) list of levels. For exmaple
   dmesg --level=err,warn
 .sp
 will print error and warning messages only.
+.IP "\fB\-x, \-\-decode\fP"
+Decode facility and level (priority) number to human readable prefixes.
 .IP "\fB\-n, \-\-console-level \fIlevel\fP
 Set the
 .I level

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index c7f5cd65f42915b53e596e1d70ea36a459ef6147..1a71af30dabd2c21d9e0b4d1d91db53e9b4a1e05 100644 (file)
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -82,10 +82,36 @@ static const struct dmesg_name level_names[] =
        [LOG_DEBUG]   = { "debug", N_("debug-level messages") }
 };
 
+/*
+ * sys/syslog.h uses (f << 3) for all facility codes.
+ * We want to use the codes as array idexes, so shift back...
+ *
+ * Note that libc LOG_FAC() macro returns the base codes, not the
+ * shifted code :-)
+ */
+#define FAC_BASE(f)    ((f) >> 3)
+
+static const struct dmesg_name facility_names[] =
+{
+       [FAC_BASE(LOG_KERN)]     = { "kern",     N_("kernel messages") },
+       [FAC_BASE(LOG_USER)]     = { "user",     N_("random user-level messages") },
+       [FAC_BASE(LOG_MAIL)]     = { "mail",     N_("mail system") },
+       [FAC_BASE(LOG_DAEMON)]   = { "daemon",   N_("system daemons") },
+       [FAC_BASE(LOG_AUTH)]     = { "auth",     N_("security/authorization messages") },
+       [FAC_BASE(LOG_SYSLOG)]   = { "syslog",   N_("messages generated internally by syslogd") },
+       [FAC_BASE(LOG_LPR)]      = { "lpr",      N_("line printer subsystem") },
+       [FAC_BASE(LOG_NEWS)]     = { "news",     N_("network news subsystem") },
+       [FAC_BASE(LOG_UUCP)]     = { "uucp",     N_("UUCP subsystem") },
+       [FAC_BASE(LOG_CRON)]     = { "cron",     N_("clock daemon") },
+       [FAC_BASE(LOG_AUTHPRIV)] = { "authpriv", N_("security/authorization messages (private)") },
+       [FAC_BASE(LOG_FTP)]      = { "ftp",      N_("ftp daemon") },
+};
+
 /* dmesg flags */
 #define DMESG_FL_RAW           (1 << 1)
 #define DMESG_FL_LEVEL         (1 << 2)
 #define DMESG_FL_FACILITY      (1 << 3)
+#define DMESG_FL_DECODE                (1 << 4)
 
 static void __attribute__((__noreturn__)) usage(FILE *out)
 {
@@ -101,6 +127,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
                " -c, --read-clear          read and clear all messages\n"
                " -d, --console-off         disable printing messages to console\n"
                " -e, --console-on          enable printing messages to console\n"
+               " -x, --decode              decode facility and level to readable string\n"
                " -h, --help                display this help and exit\n"
                " -l, --level=LIST          restrict output to defined levels\n"
                " -n, --console-level=LEVEL set level of messages printed to console\n"
@@ -108,9 +135,16 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
                " -s, --buffer-size=SIZE    buffer size to query the kernel ring buffer\n"
                " -V, --version             output version information and exit\n\n"));
 
-       fprintf(out, _("Supported log levels (priorities):\n"));
+       fprintf(out, _("Supported log facilities:\n"));
        for (i = 0; i < ARRAY_SIZE(level_names); i++) {
-               fprintf(stderr, " <%d> %7s - %s\n", i,
+               fprintf(stderr, " %7s - %s\n",
+                               facility_names[i].name,
+                               _(facility_names[i].help));
+       }
+
+       fprintf(out, _("\nSupported log levels (priorities):\n"));
+       for (i = 0; i < ARRAY_SIZE(level_names); i++) {
+               fprintf(stderr, " %7s - %s\n",
                                level_names[i].name,
                                _(level_names[i].help));
        }
@@ -167,6 +201,11 @@ static const char *parse_faclev(const char *str, int *fac, int *lev)
        if (!errno && end && end > str) {
                *fac = LOG_FAC(num);
                *lev = LOG_PRI(num);
+
+               if (*lev > ARRAY_SIZE(level_names))
+                       *lev = -1;
+               if (*fac > ARRAY_SIZE(facility_names))
+                       *fac = -1;
                return end + 1;         /* skip '<' */
        }
 
@@ -288,7 +327,7 @@ static void safe_fwrite(const char *buf, size_t size, FILE *out)
                if (hex)
                        rc = fwrite_hex(p, len, out);
                else
-                       rc = write_all(fileno(out), p, len);
+                       rc = fwrite(p, 1, len, out) != len;
                if (rc != 0)
                        err(EXIT_FAILURE, _("write failed"));
        }
@@ -309,7 +348,7 @@ static void print_buffer(const char *buf, size_t size, int flags, char *levels)
 
        for (i = 0; i < size; i++) {
                const char *p = buf + i, *end = NULL;
-               int fac = 0, lev = 0;
+               int fac = -1, lev = -1;
 
                if (!begin)
                        begin = p;
@@ -325,7 +364,9 @@ static void print_buffer(const char *buf, size_t size, int flags, char *levels)
                        continue;       /* error or empty line? */
 
                if (*begin == '<') {
-                       if ((flags & DMESG_FL_LEVEL) || (flags & DMESG_FL_FACILITY)) {
+                       if ((flags & DMESG_FL_LEVEL) ||
+                           (flags & DMESG_FL_FACILITY) ||
+                           (flags & DMESG_FL_DECODE)) {
                                /* parse facility and level */
                                begin = parse_faclev(begin + 1, &fac, &lev);
                        } else {
@@ -339,9 +380,13 @@ static void print_buffer(const char *buf, size_t size, int flags, char *levels)
                }
 
                if (begin < end &&
-                   (!lev || !levels || isset(levels, lev))) {
+                   (lev < 0 || !(flags & DMESG_FL_LEVEL) || isset(levels, lev))) {
                        size_t sz =  end - begin;
 
+                       if ((flags & DMESG_FL_DECODE) && lev >= 0 && fac >= 0) {
+                               printf("%-6s:%-6s: ", facility_names[fac].name,
+                                               level_names[lev].name);
+                       }
                        safe_fwrite(begin, sz, stdout);
                        if (*(begin + sz - 1) != '\n')
                                putchar('\n');
@@ -366,6 +411,7 @@ int main(int argc, char *argv[])
                { "read-clear",    no_argument,       NULL, 'c' },
                { "raw",           no_argument,       NULL, 'r' },
                { "buffer-size",   required_argument, NULL, 's' },
+               { "decode",        no_argument,       NULL, 'x' },
                { "console-level", required_argument, NULL, 'n' },
                { "level",         required_argument, NULL, 'l' },
                { "console-off",   no_argument,       NULL, 'd' },
@@ -379,7 +425,7 @@ int main(int argc, char *argv[])
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
 
-       while ((c = getopt_long(argc, argv, "Ccdehl:rn:s:V", longopts, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "Ccdehl:rn:s:Vx", longopts, NULL)) != -1) {
 
                if (cmd != -1 && strchr("Ccnde", c))
                        errx(EXIT_FAILURE, "%s %s",
@@ -410,6 +456,9 @@ int main(int argc, char *argv[])
                case 'r':
                        flags |= DMESG_FL_RAW;
                        break;
+               case 'x':
+                       flags |= DMESG_FL_DECODE;
+                       break;
                case 's':
                        bufsize = strtol_or_err(optarg,
                                        _("failed to parse buffer size"));
@@ -437,6 +486,9 @@ int main(int argc, char *argv[])
        if (cmd == -1)
                cmd = SYSLOG_ACTION_READ_ALL;   /* default */
 
+       if ((flags & DMESG_FL_RAW) && ((flags != DMESG_FL_RAW)))
+               errx(EXIT_FAILURE, _("options --level and --facility cannot be used for raw output"));
+
        switch (cmd) {
        case SYSLOG_ACTION_READ_ALL:
        case SYSLOG_ACTION_READ_CLEAR: