From: Karel Zak <kzak@redhat.com>
Date: Wed, 21 Oct 2020 10:03:45 +0000 (+0200)
Subject: dmesg: add --since and --until
X-Git-Tag: v2.37-rc1~405
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=732d75945ef5a299f08d60c6f8b28152b8b38bbc;p=thirdparty%2Futil-linux.git

dmesg: add --since and --until

$ date
Wed 21 Oct 2020 12:05:07 PM CEST

$ dmesg --ctime --since '1 hour ago'
[Wed Oct 21 11:47:13 2020] AAA
[Wed Oct 21 11:55:48 2020] BBB

$ dmesg --ctime --since '1 hour ago' --until '10 minutes ago'
[Wed Oct 21 11:47:13 2020] AAA

Addresses: https://github.com/karelzak/util-linux/issues/1166
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/bash-completion/dmesg b/bash-completion/dmesg
index 02f2fc7a62..00772993c2 100644
--- a/bash-completion/dmesg
+++ b/bash-completion/dmesg
@@ -57,6 +57,8 @@ _dmesg_module()
 		--follow
 		--follow-new
 		--decode
+		--since
+		--until
 		--help
 		--version"
 	COMPREPLY=( $(compgen -W "${OPTS[*]}" -- $cur) )
diff --git a/sys-utils/dmesg.1 b/sys-utils/dmesg.1
index 4bec7892bb..b38766826c 100644
--- a/sys-utils/dmesg.1
+++ b/sys-utils/dmesg.1
@@ -162,6 +162,14 @@ system
 .BR SUSPEND / RESUME .
 Timestamps are adjusted according to current delta between boottime and monotonic
 clocks, this works only for messages printed after last resume.
+.IP "\fB\-\-since \fItime\fR"
+Display record since the specified time.  The time is possible to specify in absolute way
+as well as by relative notation (e.g. '1 hour ago').  Be aware that the timestamp could
+be inaccurate and see \fB\-\-ctime\fR for more details.
+.IP "\fB\-\-until \fItime\fR"
+Display record until the specified time.  The time is possible to specify in absolute way
+as well as by relative notation (e.g. '1 hour ago').  Be aware that the timestamp could
+be inaccurate and see \fB\-\-ctime\fR for more details.
 .IP "\fB\-t\fR, \fB\-\-notime\fR"
 Do not print kernel's timestamps.
 .IP "\fB\-\-time\-format\fR \fIformat\fR"
diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index c7759857e2..fa1dd2dffc 100644
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -180,6 +180,9 @@ struct dmesg_control {
 	ssize_t		kmsg_first_read;/* initial read() return code */
 	char		kmsg_buf[BUFSIZ];/* buffer to read kmsg data */
 
+	time_t		since;		/* filter records by time */
+	time_t		until;		/* filter records by time */
+
 	/*
 	 * For the --file option we mmap whole file. The unnecessary (already
 	 * printed) pages are always unmapped. The result is that we have in
@@ -303,6 +306,9 @@ static void __attribute__((__noreturn__)) usage(void)
 	fputs(_("     --time-format <format>  show timestamp using the given format:\n"
 		"                               [delta|reltime|ctime|notime|iso]\n"
 		"Suspending/resume will make ctime and iso timestamps inaccurate.\n"), out);
+	fputs(_("     --since <time>          display the lines since the specified time\n"), out);
+	fputs(_("     --until <time>          display the lines until the specified time\n"), out);
+
 	fputs(USAGE_SEPARATOR, out);
 	printf(USAGE_HELP_OPTIONS(29));
 	fputs(_("\nSupported log facilities:\n"), out);
@@ -778,6 +784,11 @@ static int get_next_syslog_record(struct dmesg_control *ctl,
 	return 1;
 }
 
+static time_t record_time(struct dmesg_control *ctl, struct dmesg_record *rec)
+{
+	return ctl->boot_time.tv_sec + ctl->suspended_time + rec->tv.tv_sec;
+}
+
 static int accept_record(struct dmesg_control *ctl, struct dmesg_record *rec)
 {
 	if (ctl->fltr_lev && (rec->facility < 0 ||
@@ -788,6 +799,12 @@ static int accept_record(struct dmesg_control *ctl, struct dmesg_record *rec)
 			      !isset(ctl->facilities, rec->facility)))
 		return 0;
 
+	if (ctl->since && ctl->since >= record_time(ctl, rec))
+		return 0;
+
+	if (ctl->until && ctl->until <= record_time(ctl, rec))
+		return 0;
+
 	return 1;
 }
 
@@ -825,7 +842,7 @@ static struct tm *record_localtime(struct dmesg_control *ctl,
 				   struct dmesg_record *rec,
 				   struct tm *tm)
 {
-	time_t t = ctl->boot_time.tv_sec + ctl->suspended_time + rec->tv.tv_sec;
+	time_t t = record_time(ctl, rec);
 	return localtime_r(&t, tm);
 }
 
@@ -1333,7 +1350,9 @@ int main(int argc, char *argv[])
 	int colormode = UL_COLORMODE_UNDEF;
 	enum {
 		OPT_TIME_FORMAT = CHAR_MAX + 1,
-		OPT_NOESC
+		OPT_NOESC,
+		OPT_SINCE,
+		OPT_UNTIL
 	};
 
 	static const struct option longopts[] = {
@@ -1352,6 +1371,7 @@ int main(int argc, char *argv[])
 		{ "help",          no_argument,	      NULL, 'h' },
 		{ "kernel",        no_argument,       NULL, 'k' },
 		{ "level",         required_argument, NULL, 'l' },
+		{ "since",	   required_argument, NULL, OPT_SINCE },
 		{ "syslog",        no_argument,       NULL, 'S' },
 		{ "raw",           no_argument,       NULL, 'r' },
 		{ "read-clear",    no_argument,	      NULL, 'c' },
@@ -1361,6 +1381,7 @@ int main(int argc, char *argv[])
 		{ "noescape",      no_argument,       NULL, OPT_NOESC },
 		{ "notime",        no_argument,       NULL, 't' },
 		{ "nopager",       no_argument,       NULL, 'P' },
+		{ "until",         required_argument, NULL, OPT_UNTIL },
 		{ "userspace",     no_argument,       NULL, 'u' },
 		{ "version",       no_argument,	      NULL, 'V' },
 		{ "time-format",   required_argument, NULL, OPT_TIME_FORMAT },
@@ -1491,7 +1512,22 @@ int main(int argc, char *argv[])
 		case OPT_NOESC:
 			ctl.noesc = 1;
 			break;
-
+		case OPT_SINCE:
+		{
+			usec_t p;
+			if (parse_timestamp(optarg, &p) < 0)
+				errx(EXIT_FAILURE, _("invalid time value \"%s\""), optarg);
+			ctl.since = (time_t) (p / 1000000);
+			break;
+		}
+		case OPT_UNTIL:
+		{
+			usec_t p;
+			if (parse_timestamp(optarg, &p) < 0)
+				errx(EXIT_FAILURE, _("invalid time value \"%s\""), optarg);
+			ctl.until = (time_t) (p / 1000000);
+			break;
+		}
 		case 'h':
 			usage();
 		case 'V':