sleep is a Unix command line program that suspends program execution for a specified period of time. The sleep instruction suspends the calling process for at least the specified number of seconds (the default), minutes, hours or days.
Where number is a integer number to indicate the time period. Some implementations may support floating point numbers.
Causes the current terminal session to wait 5 seconds.
Causes the current terminal session to wait 5 hours
GNU sleep specific Examples
sleep 3h ; mplayer foo.mp3
Wait 3 hours then play foo.mp3
Note that sleep 5h30m and sleep 5h 30m are illegal since sleep takes only one value and unit as argument. However, sleep 5.5h is allowed. Consecutive executions of sleep can also be used.
sleep 5h; sleep 30m
The sleep command pauses for an amount of time defined by NUMBER.
SUFFIX may be “s” for seconds (the default), “m” for minutes, “h” for hours, or “d” for days.
Some implementations require that NUMBER be an integer, but modern Linux implementations allow NUMBER to also be a floating-point value.
If more than one NUMBER is specified, sleep delays for the sum of their values.