err.3: EXAMPLES: use EXIT_FAILURE rather than 1 as exit status

[thirdparty/man-pages.git] / man3 / sleep.3

diff --git a/man3/sleep.3 b/man3/sleep.3
index e50d6172684640b9d6eed4cd70cc9723df4fe94d..db50baa9513d6cacec726266e40fb3ae7e91eef1 100644 (file)
--- a/man3/sleep.3
+++ b/man3/sleep.3
@@ -23,30 +23,56 @@
 .\" %%%LICENSE_END
 .\"
 .\" Modified Sat Jul 24 18:16:02 1993 by Rik Faith (faith@cs.unc.edu)
-.TH SLEEP 3  2010-02-03 "GNU" "Linux Programmer's Manual"
+.TH SLEEP 3  2017-09-15 "GNU" "Linux Programmer's Manual"
 .SH NAME
-sleep \- sleep for the specified number of seconds
+sleep \- sleep for a specified number of seconds
 .SH SYNOPSIS
 .nf
 .B #include <unistd.h>
-.sp
+.PP
 .BI "unsigned int sleep(unsigned int " "seconds" );
 .fi
 .SH DESCRIPTION
 .BR sleep ()
-makes the calling thread sleep until
+causes the calling thread to sleep either until
+the number of real-time seconds specified in
 .I seconds
-seconds have elapsed or a signal arrives which is not ignored.
+have elapsed or until a signal arrives which is not ignored.
 .SH RETURN VALUE
 Zero if the requested time has elapsed,
 or the number of seconds left to sleep,
 if the call was interrupted by a signal handler.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lb lb lbw27
+l l l.
+Interface      Attribute       Value
+T{
+.BR sleep ()
+T}     Thread safety   MT-Unsafe sig:SIGCHLD/linux
+.TE
+.sp 1
 .SH CONFORMING TO
-POSIX.1-2001.
-.SH BUGS
+POSIX.1-2001, POSIX.1-2008.
+.SH NOTES
+On Linux,
+.BR sleep ()
+is implemented via
+.BR nanosleep (2).
+See the
+.BR nanosleep (2)
+man page for a discussion of the clock used.
+.SS Portability notes
+On some systems,
 .BR sleep ()
 may be implemented using
-.BR SIGALRM ;
+.BR alarm (2)
+and
+.BR SIGALRM
+(POSIX.1 permits this);
 mixing calls to
 .BR alarm (2)
 and
@@ -59,6 +85,7 @@ from a signal handler or modifying the handling of
 .B SIGALRM
 while sleeping will cause undefined results.
 .SH SEE ALSO
+.BR sleep (1),
 .BR alarm (2),
 .BR nanosleep (2),
 .BR signal (2),