dmesg: add --show-delta option

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

diff --git a/sys-utils/dmesg.1 b/sys-utils/dmesg.1
index d86aceea036de5afd465b763608cb0b110af46b7..a9cb4bedaafef06fd6c04d452d3ee97f98ee6970 100644 (file)
--- a/sys-utils/dmesg.1
+++ b/sys-utils/dmesg.1
@@ -32,9 +32,11 @@ options are mutually exclusive.
 Clear the ring buffer.
 .IP "\fB\-c, \-\-read-clear\fP"
 Clear the ring buffer contents after printing.
-.IP "\fB\-d, \-\-console-off\fP"
+.IP "\fB\-D, \-\-console-off\fP"
 Disable printing messages to the console.
-.IP "\fB\-e, \-\-console-on\fP"
+.IP "\fB\-d, \-\-show-delta\fP"
+Display the time spent between messages.
+.IP "\fB\-E, \-\-console-on\fP"
 Enable printing messages to the console.
 .IP "\fB\-f, \-\-facility \fIlist\fP"
 Restrict output to defined (comma separated) list of facilities. For example

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index 5cf69dbafcb75218463c75fa7a3a49f26443f7be..0c7ab67337af4a1469d8cf7cdd4800b08c28778c 100644 (file)
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -12,7 +12,9 @@
 #include <stdlib.h>
 #include <sys/klog.h>
 #include <sys/syslog.h>
+#include <sys/time.h>
 #include <ctype.h>
+#include <time.h>
 
 #include "c.h"
 #include "nls.h"
@@ -98,11 +100,14 @@ struct dmesg_control {
        char levels[ARRAY_SIZE(level_names) / NBBY + 1];
        char facilities[ARRAY_SIZE(facility_names) / NBBY + 1];
 
+       struct timeval  lasttime;       /* last printed timestamp */
+
        int     raw:1;                  /* raw mode */
        int     fltr_lev:1;             /* filter out by levels[] */
        int     fltr_fac:1;             /* filter out by facilities[] */
        int     decode:1;               /* use "facility: level: " prefix */
        int     notime:1;               /* don't print timestamp */
+       int     delta:1;                /* show time deltas */
 };
 
 struct dmesg_record {
@@ -111,6 +116,7 @@ struct dmesg_record {
 
        int             level;
        int             facility;
+       struct timeval  tv;
 
        const char      *next;          /* buffer with next unparsed record */
        size_t          next_size;      /* size of the next buffer */
@@ -128,8 +134,9 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
                "\nOptions:\n"
                " -C, --clear               clear the kernel ring buffer\n"
                " -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"
+               " -D, --console-off         disable printing messages to console\n"
+               " -d, --show-delta          show time delta between printed messages\n"
+               " -E, --console-on          enable printing messages to console\n"
                " -f, --facility=LIST       restrict output to defined facilities\n"
                " -h, --help                display this help and exit\n"
                " -k, --kernel              display kernel messages\n"
@@ -271,6 +278,34 @@ static const char *parse_faclev(const char *str, int *fac, int *lev)
        return str;
 }
 
+static const char *parse_timestamp(const char *str0, struct timeval *tv)
+{
+       const char *str = str0;
+       char *end = NULL;
+
+       if (!str0)
+               return str0;
+
+       errno = 0;
+       tv->tv_sec = strtol(str, &end, 10);
+
+       if (!errno && end && *end == '.' && *(end + 1)) {
+               str = end + 1;
+               end = NULL;
+               tv->tv_usec = strtol(str, &end, 10);
+       }
+       if (errno || !end || end == str || *end != ']')
+               return str0;
+
+       return end + 1; /* skip ']' */
+}
+
+
+static double time_diff(struct timeval *a, struct timeval *b)
+{
+       return (a->tv_sec - b->tv_sec) + (a->tv_usec - b->tv_usec) / 1E6;
+}
+
 /*
  * LIST ::= <item> [, <item>]
  *
@@ -417,6 +452,8 @@ static int get_next_record(struct dmesg_control *ctl, struct dmesg_record *rec)
        rec->mesg_size = 0;
        rec->facility = -1;
        rec->level = -1;
+       rec->tv.tv_sec = 0;
+       rec->tv.tv_usec = 0;
 
        for (i = 0; i < rec->next_size; i++) {
                const char *p = rec->next + i;
@@ -439,7 +476,6 @@ static int get_next_record(struct dmesg_control *ctl, struct dmesg_record *rec)
 
                if (*begin == '<') {
                        if (ctl->fltr_lev || ctl->fltr_fac || ctl->decode) {
-                               /* parse facility and level */
                                begin = parse_faclev(begin + 1, &rec->facility,
                                                     &rec->level);
                        } else {
@@ -455,13 +491,16 @@ static int get_next_record(struct dmesg_control *ctl, struct dmesg_record *rec)
                if (end <= begin)
                        return -1;      /* error */
 
-               if (ctl->notime && *begin == '[' &&
-                   (*(begin + 1) == ' ' || isdigit(*(begin + 1)))) {
-                       /* ignore timestamp */
-                       while (begin < end) {
-                               begin++;
-                               if (*(begin - 1) == ']')
-                                       break;
+               if (*begin == '[' && (*(begin + 1) == ' ' ||
+                                     isdigit(*(begin + 1)))) {
+                       if (ctl->notime) {              /* ignore timestamp */
+                               while (begin < end) {
+                                       begin++;
+                                       if (*(begin - 1) == ']')
+                                               break;
+                               }
+                       } else if (ctl->delta) {
+                               begin = parse_timestamp(begin + 1, &rec->tv);
                        }
                }
 
@@ -510,7 +549,10 @@ static void print_buffer(const char *buf, size_t size,
                return;
        }
 
-       while (get_next_record(ctl, &rec) == 0 && rec.mesg_size) {
+       while (get_next_record(ctl, &rec) == 0) {
+
+               if (!rec.mesg_size)
+                       continue;
 
                if (!accept_record(ctl, &rec))
                        continue;
@@ -519,6 +561,18 @@ static void print_buffer(const char *buf, size_t size,
                        printf("%-6s:%-6s: ", facility_names[rec.facility].name,
                                              level_names[rec.level].name);
 
+               if (ctl->delta) {
+                       double delta = 0;
+
+                       if (ctl->lasttime.tv_sec && ctl->lasttime.tv_usec)
+                               delta = time_diff(&rec.tv, &ctl->lasttime);
+                       ctl->lasttime = rec.tv;
+
+                       printf("[%5d.%06d <%12.06f>] ",
+                                       (int) rec.tv.tv_sec,
+                                       (int) rec.tv.tv_usec, delta);
+               }
+
                safe_fwrite(rec.mesg, rec.mesg_size, stdout);
 
                if (*(rec.mesg + rec.mesg_size - 1) != '\n')
@@ -540,8 +594,8 @@ int main(int argc, char *argv[])
                { "buffer-size",   required_argument, NULL, 's' },
                { "clear",         no_argument,       NULL, 'C' },
                { "console-level", required_argument, NULL, 'n' },
-               { "console-off",   no_argument,       NULL, 'd' },
-               { "console-on",    no_argument,       NULL, 'e' },
+               { "console-off",   no_argument,       NULL, 'D' },
+               { "console-on",    no_argument,       NULL, 'E' },
                { "decode",        no_argument,       NULL, 'x' },
                { "facility",      required_argument, NULL, 'f' },
                { "help",          no_argument,       NULL, 'h' },
@@ -549,6 +603,7 @@ int main(int argc, char *argv[])
                { "level",         required_argument, NULL, 'l' },
                { "raw",           no_argument,       NULL, 'r' },
                { "read-clear",    no_argument,       NULL, 'c' },
+               { "show-delta",    no_argument,       NULL, 'd' },
                { "notime",        no_argument,       NULL, 't' },
                { "userspace",     no_argument,       NULL, 'u' },
                { "version",       no_argument,       NULL, 'V' },
@@ -559,10 +614,10 @@ int main(int argc, char *argv[])
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
 
-       while ((c = getopt_long(argc, argv, "Ccdef:hkl:n:rs:tuVx",
+       while ((c = getopt_long(argc, argv, "CcDdEf:hkl:n:rs:tuVx",
                                longopts, NULL)) != -1) {
 
-               if (cmd != -1 && strchr("Ccnde", c))
+               if (cmd != -1 && strchr("CcnDE", c))
                        errx(EXIT_FAILURE, "%s %s",
                                "--{clear,read-clear,console-level,console-on,console-off}",
                                _("options are mutually exclusive"));
@@ -574,10 +629,13 @@ int main(int argc, char *argv[])
                case 'c':
                        cmd = SYSLOG_ACTION_READ_CLEAR;
                        break;
-               case 'd':
+               case 'D':
                        cmd = SYSLOG_ACTION_CONSOLE_OFF;
                        break;
-               case 'e':
+               case 'd':
+                       ctl.delta = 1;
+                       break;
+               case 'E':
                        cmd = SYSLOG_ACTION_CONSOLE_ON;
                        break;
                case 'f':