coreutils: sleep invocation

1 
1 25.1 ‘sleep’: Delay for a specified time
1 ========================================
1 
1 ‘sleep’ pauses for an amount of time specified by the sum of the values
1 of the command line arguments.  Synopsis:
1 
1      sleep NUMBER[smhd]...
1 
1    Each argument is a number followed by an optional unit; the default
1 is seconds.  The units are:
1 
1 ‘s’
1      seconds
1 ‘m’
1      minutes
1 ‘h’
1      hours
1 ‘d’
1      days
1 
1    Historical implementations of ‘sleep’ have required that NUMBER be an
1 integer, and only accepted a single argument without a suffix.  However,
11 GNU ‘sleep’ accepts arbitrary floating point numbers.  ⇒Floating
 point.
1 
11    The only options are ‘--help’ and ‘--version’.  ⇒Common
 options.
1 
1    Due to shell aliases and built-in ‘sleep’ functions, using an
1 unadorned ‘sleep’ interactively or in a script may get you different
1 functionality than that described here.  Invoke it via ‘env’ (i.e., ‘env
1 sleep ...’) to avoid interference from the shell.
1 
1    An exit status of zero indicates success, and a nonzero value
1 indicates failure.
1