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nanosleep — suspend process execution for an interval measured in
Standard C Library (libc, -lc)
nanosleep(const struct timespec *rqtp, struct timespec *rmtp);
The nanosleep() system call causes the calling thread to sleep until the
time interval specified by rqtp has elapsed. An unmasked signal will
cause it to terminate the sleep early, regardless of the SA_RESTART value
on the interrupting signal.
If the nanosleep() system call returns because the requested time has
elapsed, the value returned will be zero.
If the nanosleep() system call returns due to the delivery of a signal,
the value returned will be -1, and the global variable errno will be set
to indicate the interruption. If rmtp is non-NULL, the timespec
structure it references is updated to contain the unslept amount (the
request time minus the time actually slept).
The nanosleep() system call fails if:
[EFAULT] Either rqtp or rmtp points to memory that is not a
valid part of the process address space.
[EINTR] The nanosleep() system call was interrupted by the
delivery of a signal.
[EINVAL] The rqtp argument specified a nanosecond value less
than zero or greater than or equal to 1000 million.
[ENOSYS] The nanosleep() system call is not supported by this
The nanosleep() system call conforms to IEEE Std 1003.1b-1993