From 5895145874af81575fdde667d6d7d91dd3a66521 Mon Sep 17 00:00:00 2001
From: kib <kib@FreeBSD.org>
Date: Sat, 31 Jul 2010 14:30:11 +0000
Subject: Report the time left for the sleep on SIGINFO. Be stricter in the
 checking of interval specification.

PR:	bin/139345
MFC after:	3 weeks
---
 bin/sleep/sleep.c | 66 +++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 47 insertions(+), 19 deletions(-)

(limited to 'bin/sleep')

diff --git a/bin/sleep/sleep.c b/bin/sleep/sleep.c
index f38b183..a573cb5 100644
--- a/bin/sleep/sleep.c
+++ b/bin/sleep/sleep.c
@@ -42,26 +42,34 @@ static char sccsid[] = "@(#)sleep.c	8.3 (Berkeley) 4/2/94";
 __FBSDID("$FreeBSD$");
 
 #include <ctype.h>
+#include <err.h>
 #include <limits.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 
-void usage(void);
+static void usage(void);
+
+static volatile sig_atomic_t report_requested;
+static void
+report_request(int signo __unused)
+{
+
+	report_requested = 1;
+}
 
 int
 main(int argc, char *argv[])
 {
 	struct timespec time_to_sleep;
-	long l;
+	long l, original;
 	int neg;
 	char *p;
 
-	if (argc != 2) {
+	if (argc != 2)
 		usage();
-		return(1);
-	}
 
 	p = argv[1];
 
@@ -74,10 +82,8 @@ main(int argc, char *argv[])
 	if (*p == '-') {
 		neg = 1;
 		++p;
-		if (!isdigit((unsigned char)*p) && *p != '.') {
+		if (!isdigit((unsigned char)*p) && *p != '.')
 			usage();
-			return(1);
-		}
 	}
 	else if (*p == '+')
 		++p;
@@ -85,13 +91,13 @@ main(int argc, char *argv[])
 	/* Calculate seconds. */
 	if (isdigit((unsigned char)*p)) {
 		l = strtol(p, &p, 10);
-		if (l > INT_MAX) {
-			/*
-			 * Avoid overflow when `seconds' is huge.  This assumes
-			 * that the maximum value for a time_t is <= INT_MAX.
-			 */
+
+		/*
+		 * Avoid overflow when `seconds' is huge.  This assumes
+		 * that the maximum value for a time_t is <= INT_MAX.
+		 */
+		if (l > INT_MAX)
 			l = INT_MAX;
-		}
 	} else
 		l = 0;
 	time_to_sleep.tv_sec = (time_t)l;
@@ -110,16 +116,38 @@ main(int argc, char *argv[])
 		} while (l);
 	}
 
-	if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0))
-		(void)nanosleep(&time_to_sleep, (struct timespec *)NULL);
+	/* Skip over the trailing whitespace. */
+	while (isspace((unsigned char)*p))
+		++p;
+	if (*p != '\0')
+		usage();
+
+	signal(SIGINFO, report_request);
+	if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0)) {
+		original = time_to_sleep.tv_sec;
+		while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
+			if (report_requested) {
+				/*
+				 * Reporting does not bother with
+				 * fractions of a second...
+				 */
+				warnx("about %ld second(s) left"
+				    " out of the original %ld",
+				    time_to_sleep.tv_sec, original);
+				report_requested = 0;
+			} else
+				break;
+		}
+	}
 
-	return(0);
+	return (0);
 }
 
-void
+static void
 usage(void)
 {
-	const char msg[] = "usage: sleep seconds\n";
+	static const char msg[] = "usage: sleep seconds\n";
 
 	write(STDERR_FILENO, msg, sizeof(msg) - 1);
+	exit(1);
 }
-- 
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