Name | Synopsis | Description | Operands | Examples | Environment Variables | Exit Status | Attributes | See Also | Notes
/usr/bin/sleep seconds
sleep seconds
sleep 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 normally depends on the underlying system.
The following operands are supported for /usr/bin/sleep and ksh93's sleep built-in command:
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".
The following example executes a command after a certain amount of time:
example% (sleep 105; command)& |
The following example executes a command every so often:
example% while true do command sleep 37 done |
example% sleep Inf |
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 |
See environ(5) for descriptions of the following environment variables that affect the execution of sleep: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned:
The execution was successfully suspended for at least time seconds, or a SIGALRM signal was received (see NOTES).
An error has occurred.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
---|---|
Availability |
SUNWcsu |
Interface Stability |
Committed |
Standard |
See standards(5). |
If the sleep utility receives a SIGALRM signal, one of the following actions is taken:
Terminate normally with a zero exit status.
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.
Name | Synopsis | Description | Operands | Examples | Environment Variables | Exit Status | Attributes | See Also | Notes