SLEEP(1) User Commands SLEEP(1)

suspend execution for an interval

sleep time[suffix]

sleep suspends execution for at least the time in seconds specified by time or until a SIGALRM signal is received. The time operand can be specified as a non-negative floating point number but the actual granularity depends on the underlying system. The time operand may be passed as a decimal or hexadecimal string. Other floating point values such as Inf or infinity are also honored.

A single suffix may be applied to the time operand to represent units other than seconds. Supported suffixes for the suffix operand include:

Represents time in seconds.
Represents time in minutes.
Represents time in hours.
Represents time in days.
Represents time in weeks.
Represents time in years.

The use of suffixes is generally not portable to other systems.

If the sleep program receives a signal, unless it is the SIGALRM signal, it will follow with the default signal handling disposition. If such a signal would interrupt the sleep, then the program may terminate with an error.

The following exit values are returned:
The execution was successfully suspended for at least time seconds, or a SIGALRM signal was received.
An error has occurred.

Example 1 Suspending Command Execution

The following example executes a command after a certain amount of time:

example% (sleep 105; command)&

Example 2 Executing a Command Every So Often

The following example executes a command every so often:

example% while true; do
        sleep 37

Example 3 Suspend command execution forever (or until a SIGALRM signal is received)

example% sleep Inf

Example 4 Suspending command execution for 0.5 seconds

Suspending command execution for 0.5 seconds using an alternative floating-point representation for the value "0.5".

example% printf "%a\n" 0.5
example% sleep 0x1.0000000000000000000000000000p-01

See environ(7) for descriptions of the following environment variables that affect the execution of sleep: LANG, LC_ALL, LC_MESSAGES, LC_NUMERIC, and NLSPATH.


wait(1), alarm(2), nanosleep(3C), sleep(3C), environ(7)
September 12, 2019 OmniOS