sleep

SLEEP(3)                   Linux Programmer's Manual                  SLEEP(3)



NAME
       sleep - sleep for a specified number of seconds

SYNOPSIS
       #include <unistd.h>

       unsigned int sleep(unsigned int seconds);

DESCRIPTION
       sleep() causes the calling thread to sleep either until the number of
       real-time seconds specified in seconds have elapsed or until a signal
       arrives which is not ignored.

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.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────┬───────────────┬─────────────────────────────┐
       │Interface Attribute     Value                       │
       ├──────────┼───────────────┼─────────────────────────────┤
       │sleep()   │ Thread safety │ MT-Unsafe sig:SIGCHLD/linux │
       └──────────┴───────────────┴─────────────────────────────┘

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

NOTES
       On Linux, sleep() is implemented via nanosleep(2).  See the
       nanosleep(2) man page for a discussion of the clock used.

   Portability notes
       On some systems, sleep() may be implemented using alarm(2) and SIGALRM
       (POSIX.1 permits this); mixing calls to alarm(2) and sleep() is a bad
       idea.

       Using longjmp(3) from a signal handler or modifying the handling of
       SIGALRM while sleeping will cause undefined results.

SEE ALSO
       sleep(1), alarm(2), nanosleep(2), signal(2), signal(7)

COLOPHON
       This page is part of release 5.04 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



GNU                               2017-09-15                          SLEEP(3)