sleep - Suspends execution for at least the specified time
Interfaces documented on this reference page conform to industry standards as follows:
sleep: XPG4, XPG4-UNIX
Refer to the
reference page for more information
about industry standards and associated tags.
Non-negative integer specifying the number of seconds for
which execution is to be suspended.
The sleep command suspends execution of a process for at least the interval specified by seconds, which can range from 0 to 2,147,483,647 seconds. Depending on system activity, the actual time of suspension may be longer. See the sleep(3) reference page.
can be entered as a non-negative
decimal, octal, or hexadecimal value.
before process execution has resumed,
takes one of
the following actions:
Terminates normally with a 0 (zero) exit status. (See the
reference page for more information.)
Ignores the signal
Performs default processing
The following exit values are returned:
Execution was successfully suspended for at least the requested
time, or a
signal was received.
An error occurred.
To display a message at 4-minute intervals for 20 minutes, create a shell script called remind containing the following:
The following environment variables affect the execution of
Provides a default value for the internationalization variables
that are unset or null. If
is unset or null, the corresponding value from the default locale is used.
If any of the internationalization variables contain an invalid setting, the
utility behaves as if none of the variables had been defined.
If set to a non-empty string value, overrides the values of
all the other internationalization variables.
Determines the locale for the interpretation of sequences
of bytes of text data as characters (for example, single-byte as opposed to
multibyte characters in arguments).
Determines the locale for the format and contents of diagnostic
messages written to standard error.
Determines the location of message catalogues for the processing
Functions: alarm(3), pause(3), sigaction(2), sleep(3)