NAME

       sleep - sleep for the specified number of seconds

SYNOPSIS

       #include <unistd.h>

       unsigned int sleep(unsigned int seconds);

DESCRIPTION

       sleep()  makes  the  calling  thread  sleep until seconds seconds have elapsed or 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.

BUGS

       sleep()  may  be  implemented using SIGALRM; 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

       alarm(2), nanosleep(2), signal(2), signal(7)

COLOPHON

       This  page  is  part of release 4.04 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 http://www.kernel.org/doc/man-pages/.