SLEEP(1)SLEEP(1)NAMEsleep - suspend execution for an interval
SYNOPSIS
/usr/bin/sleep
/usr/bin/sleep seconds
ksh93
sleep seconds
DESCRIPTIONsleep suspends execution for at least the time in seconds specified by
seconds or until a SIGALRM signal is received. The seconds operand can
be specified as a floating point number but the actual granularity nor‐
mally depends on the underlying system.
OPERANDS
/usr/bin/sleep
The following operands are supported for /usr/bin/sleep and ksh93's
sleep built-in command:
seconds
A non-negative floating-point number specifying the number
of seconds for which to suspend execution. The floating-
point number may be specified in all formats required by
C99/XPG6, including constants such as "Inf" or "infinite".
ksh93
The following operands are supported:
time
Specify time in seconds as a floating point number. The actual
granularity depends on the underlying system, normally around 1
millisecond.
EXAMPLES
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
command
sleep 37
done
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
0x1.0000000000000000000000000000p-01
example% sleep 0x1.0000000000000000000000000000p-01
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables
that affect the execution of sleep: LANG, LC_ALL, LC_CTYPE, LC_MES‐
SAGES, and NLSPATH.
EXIT STATUS
The following exit values are returned:
0
The execution was successfully suspended for at least time sec‐
onds, or a SIGALRM signal was received (see NOTES).
>0
An error has occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
/usr/bin/sleep
┌────────────────────┬───────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼───────────────────┤
│Interface Stability │ Committed │
├────────────────────┼───────────────────┤
│Standard │ See standards(5). │
└────────────────────┴───────────────────┘
ksh93
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Uncommitted │
└────────────────────┴─────────────────┘
SEE ALSOksh93(1), wait(1), alarm(2), sleep(3C), wait(3UCB), attributes(5), env‐
iron(5), standards(5)NOTES
If the sleep utility receives a SIGALRM signal, one of the following
actions is taken:
o Terminate normally with a zero exit status.
o Effectively ignore the signal.
The sleep utility takes the standard action for all other signals.
The behavior for input values such as "NaN" (not-a-number) or negative
values is undefined.
Sep 10, 2013 SLEEP(1)
