shell: modules: Add date commands to display or set date

Currently only supports Unix time.

‘get’ subcommand returns date in format “Y-m-d H:M:S”
‘set’ subcommand format is ‘[Y-m-d] <H:M:S>’

The ‘set’ subcommand is implemented with basic date validation.

For user convenience of small adjustments to time the time argument
will accept H:M:S, :M:S or ::S where the missing field(s) will be
filled in by the previous time state.

Signed-off-by: Nick Ward <nix.ward@gmail.com>

subsys/shell/modules/CMakeLists.txt

@@ -8,3 +8,7 @@ zephyr_sources_ifdef(
   CONFIG_DEVICE_SHELL
   device_service.c
   )
+zephyr_sources_ifdef(
+  CONFIG_DATE_SHELL
+  date_service.c
+  )

subsys/shell/modules/Kconfig

@@ -13,3 +13,9 @@ config DEVICE_SHELL
 	bool "Enable device shell"
 	help
 	  This shell provides access to basic device data.
+
+config DATE_SHELL
+	bool "Enable date shell"
+	depends on POSIX_CLOCK
+	help
+	  This shell provides access to date and time based on Unix time.

subsys/shell/modules/date_service.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2020 Nick Ward
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+#include <shell/shell.h>
+#include <init.h>
+#include <string.h>
+#include <posix/time.h>
+#include <sys/timeutil.h>
+
+#define HELP_NONE      "[none]"
+#define HELP_DATE_SET  "[Y-m-d] <H:M:S>"
+
+static void date_print(const struct shell *shell, struct tm *tm)
+{
+	shell_print(shell,
+		    "%d-%02u-%02u "
+		    "%02u:%02u:%02u UTC",
+		    tm->tm_year + 1900,
+		    tm->tm_mon + 1,
+		    tm->tm_mday,
+		    tm->tm_hour,
+		    tm->tm_min,
+		    tm->tm_sec);
+}
+
+static int get_y_m_d(const struct shell *shell, struct tm *tm, char *date_str)
+{
+	int year;
+	int month;
+	int day;
+	char *endptr;
+
+	endptr = NULL;
+	year = strtol(date_str, &endptr, 10);
+	if ((endptr == date_str) || (*endptr != '-')) {
+		return -EINVAL;
+	}
+
+	date_str = endptr + 1;
+
+	endptr = NULL;
+	month = strtol(date_str, &endptr, 10);
+	if ((endptr == date_str) || (*endptr != '-')) {
+		return -EINVAL;
+	}
+
+	if ((month < 1) || (month > 12)) {
+		shell_error(shell, "Invalid month");
+		return -EINVAL;
+	}
+
+	date_str = endptr + 1;
+
+	endptr = NULL;
+	day = strtol(date_str, &endptr, 10);
+	if ((endptr == date_str) || (*endptr != '\0')) {
+		return -EINVAL;
+	}
+
+	/* Check day against maximum month length */
+	if ((day < 1) || (day > 31)) {
+		shell_error(shell, "Invalid day");
+		return -EINVAL;
+	}
+
+	tm->tm_year = year - 1900;
+	tm->tm_mon = month - 1;
+	tm->tm_mday = day;
+
+	return 0;
+}
+
+/*
+ * For user convenience of small adjustments to time the time argument will
+ * accept H:M:S, :M:S or ::S where the missing field(s) will be filled in by
+ * the previous time state.
+ */
+static int get_h_m_s(const struct shell *shell, struct tm *tm, char *time_str)
+{
+	char *endptr;
+
+	if (*time_str == ':') {
+		time_str++;
+	} else {
+		endptr = NULL;
+		tm->tm_hour = strtol(time_str, &endptr, 10);
+		if (endptr == time_str) {
+			return -EINVAL;
+		} else if (*endptr == ':') {
+			if ((tm->tm_hour < 0) || (tm->tm_hour > 23)) {
+				shell_error(shell, "Invalid hour");
+				return -EINVAL;
+			}
+
+			time_str = endptr + 1;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	if (*time_str == ':') {
+		time_str++;
+	} else {
+		endptr = NULL;
+		tm->tm_min = strtol(time_str, &endptr, 10);
+		if (endptr == time_str) {
+			return -EINVAL;
+		} else if (*endptr == ':') {
+			if ((tm->tm_min < 0) || (tm->tm_min > 59)) {
+				shell_error(shell, "Invalid minute");
+				return -EINVAL;
+			}
+
+			time_str = endptr + 1;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	endptr = NULL;
+	tm->tm_sec = strtol(time_str, &endptr, 10);
+	if ((endptr == time_str) || (*endptr != '\0')) {
+		return -EINVAL;
+	}
+
+	/* Note range allows for a leap second */
+	if ((tm->tm_sec < 0) || (tm->tm_sec > 60)) {
+		shell_error(shell, "Invalid second");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cmd_date_set(const struct shell *shell, size_t argc, char **argv)
+{
+	struct timespec tp;
+	struct tm tm;
+	int ret;
+
+	clock_gettime(CLOCK_REALTIME, &tp);
+
+	gmtime_r(&tp.tv_sec, &tm);
+
+	if (argc == 3) {
+		ret = get_y_m_d(shell, &tm, argv[1]);
+		if (ret != 0) {
+			shell_help(shell);
+			return -EINVAL;
+		}
+		ret = get_h_m_s(shell, &tm, argv[2]);
+		if (ret != 0) {
+			shell_help(shell);
+			return -EINVAL;
+		}
+	} else if (argc == 2) {
+		ret = get_h_m_s(shell, &tm, argv[1]);
+		if (ret != 0) {
+			shell_help(shell);
+			return -EINVAL;
+		}
+	} else {
+		shell_help(shell);
+		return -EINVAL;
+	}
+
+	tp.tv_sec = timeutil_timegm(&tm);
+	if (tp.tv_sec == -1) {
+		shell_error(shell, "Failed to calculate seconds since Epoch");
+		return -EINVAL;
+	}
+	tp.tv_nsec = 0;
+
+	ret = clock_settime(CLOCK_REALTIME, &tp);
+	if (ret != 0) {
+		shell_error(shell, "Could not set date %d", ret);
+		return -EINVAL;
+	}
+
+	date_print(shell, &tm);
+
+	return 0;
+}
+
+static int cmd_date_get(const struct shell *shell, size_t argc, char **argv)
+{
+	struct timespec tp;
+	struct tm tm;
+
+	clock_gettime(CLOCK_REALTIME, &tp);
+
+	gmtime_r(&tp.tv_sec, &tm);
+
+	date_print(shell, &tm);
+
+	return 0;
+}
+
+SHELL_STATIC_SUBCMD_SET_CREATE(sub_date,
+	SHELL_CMD(set, NULL, HELP_DATE_SET, cmd_date_set),
+	SHELL_CMD(get, NULL, HELP_NONE, cmd_date_get),
+	SHELL_SUBCMD_SET_END /* Array terminated. */
+);
+
+SHELL_CMD_REGISTER(date, &sub_date, "Date commands", NULL);