sleep: Delay for a specified time
sleep pauses for an amount of time specified by the sum of
the values of the command line arguments.
Each argument is a non-negative number followed by an optional unit; the default is seconds. The units are:
Although portable POSIX scripts must give
sleep a single
non-negative integer argument without a suffix, GNU
also accepts two or more arguments, unit suffixes, and floating-point
numbers in either the current or the C locale. See Floating point.
The only options are --help and --version. See Common options.
Due to shell aliases and built-in
sleep functions, using an
sleep interactively or in a script may get you
different functionality than that described here. Invoke it via
env sleep …) to avoid interference
from the shell.
An exit status of zero indicates success, and a nonzero value indicates failure.