Index for Section 3

Alphabetical listing for U

Bottom of page

usleep(3)
NAME
  usleep - Suspend execution for an interval of time

SYNOPSIS
  #include <unistd.h>

  int usleep(
	  useconds_t useconds );

  The following function declaration does not conform to current standards
  and is supported only for backward compatibility:

  #include <unistd.h>

  void usleep(
	  unsigned useconds );

LIBRARY
  Standard C Library (libc)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  usleep():  XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  useconds
      Specifies the number of microseconds to sleep.

DESCRIPTION
  The usleep() function suspends the current process from execution for the
  number of microseconds specified by the useconds parameter. Because of
  other activity in the system, or because of the time spent in processing
  the call, the actual suspension time might be longer than specified.

  The useconds parameter must be less than 1,000,000.  If the value of
  useconds is 0 (zero), the usleep() function has no effect.

  In a multithreaded environment, the sleep() function is redefined to
  suspend the calling thread.

RETURN VALUES
  On successful completion, the usleep() function returns 0 (zero).
  Otherwise, it returns -1 and sets errno to indicate the error.

ERRORS
  The usleep() function sets errno to the specified values for the following
  conditions:

  [EINVAL]
      The interval specified in the useconds parameter exceeds 1,000,000
      microseconds.

SEE ALSO
  Functions: getitimer(2), sigaction(2), sigvec(2), alarm(3), sleep(3)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for U

Top of page