From d15edf7f6132be7a3b580898dd67267a833a328d Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Sat, 28 Aug 2021 21:38:33 -0400
Subject: Add loop, adjust datetime_parse() param and decls

---
(limited to 'src')

diff --git a/src/datetime.c b/src/datetime.c
index 8ceed11..8597ea2 100644
--- a/src/datetime.c
+++ b/src/datetime.c
@@ -67,12 +67,12 @@ datetime_concat_args(int argc, const char *argv[])
 }
 
 int
-datetime_parse(int argc, const char *argv[], struct tm *arg_tm)
+datetime_parse(int argc, const char *argv[], time_t *arg_sec)
 {
 	char      *buf;
 	int        i;
 	char      *end;
-	time_t     arg_sec;
+	struct tm  arg_tm;
 	time_t     now_sec;
 	struct tm *now_tm;
 
@@ -81,12 +81,13 @@ datetime_parse(int argc, const char *argv[], struct tm *arg_tm)
 		return -1;
 	}
 
-	arg_tm->tm_mday = INT_MIN;  /* Sentinel */
-	arg_tm->tm_sec  = 0;        /* Default */
+	arg_tm.tm_mday = INT_MIN;  /* Sentinel */
+	arg_tm.tm_sec  = 0;        /* Default */
+	arg_tm.tm_isdst = -1;
 
 	for (i = 0; DATETIME_FMTS_[i] != NULL; ++i) {
 		/* printf("%s =~ %s\n", buf, DATETIME_FMTS_[i]); */
-		end = strptime(buf, DATETIME_FMTS_[i], arg_tm);
+		end = strptime(buf, DATETIME_FMTS_[i], &arg_tm);
 		if (end != NULL && *end == '\0') {
 			goto found;
 		}
@@ -100,26 +101,33 @@ datetime_parse(int argc, const char *argv[], struct tm *arg_tm)
 	free(buf);
 
 	/* TODO: Support %a-only dates and optional years */
-	if (arg_tm->tm_mday == INT_MIN) {
+	if (arg_tm.tm_mday == INT_MIN) {
 		/* No date specified; try today. */
 		now_sec = time(NULL);
 		now_tm = localtime(&now_sec);
-		arg_tm->tm_year = now_tm->tm_year;
-		arg_tm->tm_mon  = now_tm->tm_mon;
-		arg_tm->tm_mday = now_tm->tm_mday;
-		arg_sec = mktime(arg_tm);
-		if (arg_sec <= mktime(now_tm)) {
+		arg_tm.tm_year = now_tm->tm_year;
+		arg_tm.tm_mon  = now_tm->tm_mon;
+		arg_tm.tm_mday = now_tm->tm_mday;
+		*arg_sec = mktime(&arg_tm);
+		if (*arg_sec <= mktime(now_tm)) {
 			/* Specified time already happened today; use tomorrow.
 			 * Adding the number of seconds in a day is a shortcut
 			 * that ignores leap seconds.  One better method would
 			 * be to increment tm_mday % days in tm_mon, etc. */
-			arg_sec += 60 * 60 * 24;
-			now_tm = localtime(&arg_sec);
-			arg_tm->tm_year = now_tm->tm_year;
-			arg_tm->tm_mon  = now_tm->tm_mon;
-			arg_tm->tm_mday = now_tm->tm_mday;
+			*arg_sec += 60 * 60 * 24;
+			now_tm = localtime(arg_sec);
+			arg_tm.tm_year = now_tm->tm_year;
+			arg_tm.tm_mon  = now_tm->tm_mon;
+			arg_tm.tm_mday = now_tm->tm_mday;
+			*arg_sec = mktime(&arg_tm);
 		}
+	} else {
+		*arg_sec = mktime(&arg_tm);
 	}
 
+	printf("%d-%02d-%02dT%02d:%02d:%02d\n", arg_tm.tm_year + 1900,
+			arg_tm.tm_mon + 1, arg_tm.tm_mday,
+			arg_tm.tm_hour, arg_tm.tm_min, arg_tm.tm_sec);
+
 	return 0;
 }
diff --git a/src/datetime.h b/src/datetime.h
index 057bc4b..e1ab3bf 100644
--- a/src/datetime.h
+++ b/src/datetime.h
@@ -21,6 +21,6 @@
 #define DATETIME_H_
 
 int
-datetime_parse(int argc, const char *argv[], struct tm *tm);
+datetime_parse(int argc, const char *argv[], time_t *arg_sec);
 
 #endif  /* DATETIME_H_ */
diff --git a/src/main.c b/src/main.c
index 45f260f..8aa97a2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -20,20 +20,32 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
+#include <unistd.h>
 #include "datetime.h"
 
 int
 main(int argc, const char *argv[])
 {
-	struct tm tm;
+	time_t arg;
+	time_t now;
+	time_t dif;
 
-	if (datetime_parse(argc - 1, argv + 1, &tm) < 0) {
+	if (datetime_parse(argc - 1, argv + 1, &arg) < 0) {
 		return EXIT_FAILURE;
 	}
 
-	printf("%d-%02d-%02dT%02d:%02d:%02d\n",
-			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-			tm.tm_hour, tm.tm_min, tm.tm_sec);
+	setvbuf(stdout, NULL, _IONBF, 0);
+	time(&now);
+	while (arg > now) {
+		dif = arg - now;
+		printf("\r%02d:%02d:%02d",
+				(int) dif / 60 / 60,
+				(int) dif / 60 % 60,
+				(int) dif      % 60);
+		sleep(1);
+		time(&now);
+	}
+	puts("");
 
 	return EXIT_SUCCESS;
 }
--
cgit v0.9.1