sleep: Delay for a specified timesleep pauses for an amount of time specified by the sum of
the values of the command line arguments.
Synopsis:
sleep number[smhd]…
Each argument is a number followed by an optional unit; the default is seconds. The units are:
seconds
minutes
hours
days
Historical implementations of sleep have required that
number be an integer, and only accepted a single argument
without a suffix. However, GNU sleep accepts
arbitrary floating point numbers. See Floating point.
The only options are --help and --version. See Common options.
Due to shell aliases and built-in sleep functions, using an
unadorned sleep interactively or in a script may get you
different functionality than that described here. Invoke it via
env (i.e., env sleep …) to avoid interference
from the shell.
An exit status of zero indicates success, and a nonzero value indicates failure.