Add posix time support

Signed-off-by: Mattias Andrée <maandree@kth.se>

3 files changed, 146 insertions, 47 deletions

diff --git a/README b/README
index 7f23ec1..c9d800d 100644
--- a/README
+++ b/README
@@ -20,6 +20,17 @@ DESCRIPTION
 	right colour for you, simply change the font
 	colour on your terminal. ☺
 
+OPTIONS
+	The mongoclock utility shall conform to the Base
+	Definitions volume of POSIX.1‐2008, Section 12.2,
+	Utility Syntax Guidelines.
+
+	The following options shall be supported:
+
+	-s	Display the posix time (seconds since
+		1970-01-01 00:00:00 UTC, ignoring inserted
+		and removed leap seconds).
+
 RATIONALE
 	It is really nice to have a large clock on your
 	computer, instead of a small clock somewhere in
diff --git a/mongoclock.1 b/mongoclock.1
index 02d9d12..46131ff 100644
--- a/mongoclock.1
+++ b/mongoclock.1
@@ -21,6 +21,19 @@ your (or if it is too large,) just change the
 font size on your terminal. If it is not the
 right colour for you, simply change the font
 colour on your terminal
+.SH OPTIONS
+The
+.B cp
+utility shall conform to the Base Definitions
+volume of POSIX.1-2008,
+.IR "Section 12.2, Utility Syntax Guidelines" .
+.PP
+The following options shall be supported:
+.TP
+.B -s
+Display the posix time (seconds since 1970-01-01
+00:00:00 UTC, ignoring inserted and removed leap
+seconds).
 .SH RATIONALE
 It is really nice to have a large clock on your
 computer, instead of a small clock somewhere in
diff --git a/mongoclock.c b/mongoclock.c
index 769e9d9..b98cc67 100644
--- a/mongoclock.c
+++ b/mongoclock.c
@@ -80,18 +80,15 @@ print_time(const char ***str, size_t y, size_t x)
 	fflush(stdout);
 }
 
-int
-main(int argc, char *argv[])
+static int
+display_time(int timerfd)
 {
-	struct tm *now;
 	const char **digits[9];
-	size_t x = 0, y = 0;
-	struct winsize winsize;
 	int small = 0;
-	int fd = -1;
-	struct itimerspec itimerspec;
 	uint64_t _overrun;
-	struct sigaction sigact;
+	struct winsize winsize;
+	size_t x = 0, y = 0;
+	struct tm *now;
 #ifdef USE_ADJTIMEX
 	struct timex timex;
 	int r;
@@ -99,42 +96,12 @@ main(int argc, char *argv[])
 	time_t now_;
 #endif
 
-	ARGBEGIN {
-	default:
-		usage();
-	} ARGEND;
-
-	if (argc)
-		usage();
-
-	fprintf(stdout, "\033[?1049h\033[?25l");
-
-	if (clock_gettime(CLOCK_REALTIME, &itimerspec.it_value))
-		goto fail;
-	itimerspec.it_interval.tv_sec = 1;
-	itimerspec.it_interval.tv_nsec = 0;
-	itimerspec.it_value.tv_sec += 1;
-	itimerspec.it_value.tv_nsec = 0;
-	fd = timerfd_create(CLOCK_REALTIME, 0);
-	if (fd < 0)
-		goto fail;
-	if (timerfd_settime(fd, TFD_TIMER_ABSTIME, &itimerspec, NULL))
-		goto fail;
-
-	memset(&sigact, 0, sizeof(sigact));
-
-	sigact.sa_handler = sigterm;
-	sigaction(SIGTERM, &sigact, NULL);
-	sigaction(SIGQUIT, &sigact, NULL);
-	sigaction(SIGINT, &sigact, NULL);
-
-	sigact.sa_handler = sigwinch;
-	sigaction(SIGWINCH, &sigact, NULL);
-
 #ifdef USE_ADJTIMEX
 	memset(&timex, 0, sizeof(timex));
 #endif
 
+	digits[8] = NULL;
+
 	while (!caught_sigterm) {
 		if (caught_sigwinch) {
 			if (ioctl(STDOUT_FILENO, (unsigned long)TIOCGWINSZ, &winsize) < 0) {
@@ -190,26 +157,134 @@ main(int argc, char *argv[])
 		digits[5] = small ? NULL : mongo_c;
 		digits[6] = mongo_ds[now->tm_sec / 10];
 		digits[7] = mongo_ds[now->tm_sec % 10];
-		digits[8] = NULL;
 
 		print_time(digits, y, x);
 
-		if (read(fd, &_overrun, sizeof(_overrun)) < 0)
+		if (read(timerfd, &_overrun, sizeof(_overrun)) < 0)
+			if (errno != EINTR)
+				goto fail;
+	}
+
+	return 0;
+
+fail:
+	return -1;
+}
+
+static int
+display_posixtime(int timerfd)
+{
+	const char **digits[21];
+	uint64_t _overrun;
+	struct winsize winsize;
+	size_t w = 0, h = 0, x, y;
+	time_t now;
+	size_t first_digit, ndigits;
+
+	digits[20] = NULL;
+
+	while (!caught_sigterm) {
+		if (caught_sigwinch) {
+			if (ioctl(STDOUT_FILENO, (unsigned long)TIOCGWINSZ, &winsize) < 0) {
+				if (errno == EINTR)
+					continue;
+				goto fail;
+			}
+			caught_sigwinch = 0;
+			h = winsize.ws_row;
+			w = winsize.ws_col;
+		}
+
+		now = time(NULL);
+		if (now < 0)
+			goto fail;
+
+		first_digit = 20;
+		do {
+			if (!first_digit)
+				abort();
+			digits[--first_digit] = mongo_ds[now % 10];
+		} while (now /= 10);
+		ndigits = 20 - first_digit;
+
+		if (h < DY || w < ndigits * DX) {
+			fprintf(stdout, "\033[H\033[2J%s\n", "Screen is too small");
+			fflush(stdout);
+			pause();
+			continue;
+		}
+
+		y = (h - DY) / 2;
+		x = (w - ndigits * DX) / 2;
+		print_time(&digits[first_digit], y, x);
+
+		if (read(timerfd, &_overrun, sizeof(_overrun)) < 0)
 			if (errno != EINTR)
 				goto fail;
 	}
 
+	return 0;
+
+fail:
+	return -1;
+}
+
+int
+main(int argc, char *argv[])
+{
+	int timerfd = -1;
+	int posixtime = 0;
+	struct itimerspec itimerspec;
+	struct sigaction sigact;
+
+	ARGBEGIN {
+	case 's':
+		posixtime = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	fprintf(stdout, "\033[?1049h\033[?25l");
+
+	if (clock_gettime(CLOCK_REALTIME, &itimerspec.it_value))
+		goto fail;
+	itimerspec.it_interval.tv_sec = 1;
+	itimerspec.it_interval.tv_nsec = 0;
+	itimerspec.it_value.tv_sec += 1;
+	itimerspec.it_value.tv_nsec = 0;
+	timerfd = timerfd_create(CLOCK_REALTIME, 0);
+	if (timerfd < 0)
+		goto fail;
+	if (timerfd_settime(timerfd, TFD_TIMER_ABSTIME, &itimerspec, NULL))
+		goto fail;
+
+	memset(&sigact, 0, sizeof(sigact));
+
+	sigact.sa_handler = sigterm;
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGINT, &sigact, NULL);
+
+	sigact.sa_handler = sigwinch;
+	sigaction(SIGWINCH, &sigact, NULL);
+
+	if (posixtime ? display_posixtime(timerfd) : display_time(timerfd))
+		goto fail;
+
 	fprintf(stdout, "\033[?25h\n\033[?1049l");
 	fflush(stdout);
-	close(fd);
+	close(timerfd);
 	return 0;
-  
+
 fail:
 	perror(argv0 ? argv0 : "mongoclock");
 	fprintf(stdout, "\033[?25h\n\033[?1049l");
 	fflush(stdout);
-	if (fd >= 0)
-		close(fd);
+	if (timerfd >= 0)
+		close(timerfd);
 	return 1;
 }
-