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sleep(1) [mojave man page]

SLEEP(1)						    BSD General Commands Manual 						  SLEEP(1)

sleep -- suspend execution for an interval of time SYNOPSIS
sleep seconds DESCRIPTION
The sleep command suspends execution for a minimum of seconds. If the sleep command receives a signal, it takes the standard action. IMPLEMENTATION NOTES
The SIGALRM signal is not handled specially by this implementation. The sleep command will accept and honor a non-integer number of specified seconds (with a '.' character as a decimal point). This is a non- portable extension, and its use will nearly guarantee that a shell script will not execute properly on another system. EXIT STATUS
The sleep utility exits 0 on success, and >0 if an error occurs. EXAMPLES
To schedule the execution of a command for x number seconds later (with csh(1)): (sleep 1800; sh command_file >& errors)& This incantation would wait a half hour before running the script command_file. (See the at(1) utility.) To reiteratively run a command (with the csh(1)): while (1) if (! -r zzz.rawdata) then sleep 300 else foreach i (`ls *.rawdata`) sleep 70 awk -f collapse_data $i >> results end break endif end The scenario for a script such as this might be: a program currently running is taking longer than expected to process a series of files, and it would be nice to have another program start processing the files created by the first program as soon as it is finished (when zzz.rawdata is created). The script checks every five minutes for the file zzz.rawdata, when the file is found, then another portion processing is done courteously by sleeping for 70 seconds in between each awk job. SEE ALSO
nanosleep(2), sleep(3) STANDARDS
The sleep command is expected to be IEEE Std 1003.2 (``POSIX.2'') compatible. HISTORY
A sleep command appeared in Version 4 AT&T UNIX. BSD
April 18, 1994 BSD

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sleep(1)						      General Commands Manual							  sleep(1)

sleep - Suspends execution for at least the specified time SYNOPSIS
sleep seconds STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: sleep: XCU5.0 Refer to the standards(5) reference page for more information about industry standards and associated tags. OPTIONS
Non-negative integer specifying the number of seconds for which execution is to be suspended. DESCRIPTION
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. [Tru64 UNIX] seconds can be entered as a non-negative decimal, octal, or hexadecimal value. NOTES
If sleep receives a SIGALARM signal before process execution has resumed, sleep takes one of the following actions: Terminates normally with a 0 (zero) exit status. (See the sleep(3) reference page for more information.) Ignores the signal Performs default processing EXIT STATUS
The following exit values are returned: Execution was successfully suspended for at least the requested time, or a SIGALARM signal was received. An error occurred. EXAMPLES
To display a message at 4-minute intervals for 20 minutes, create a shell script called remind containing the following: for i do sleep 240; echo $i sleep 240; echo $i sleep 240; echo $i sleep 240; echo $i sleep 240; echo $i done To display the message Try calling NHK at 4-minute intervals, enter: remind 'Try calling NHK' To run a command at regular intervals, create a shell script containing the following: while true do date sleep 60 done This displays the date and time once a minute. To execute a command after a specified interval, enter the following; (sleep 3600; echo Time's up) & This displays the message "Time's up" after one hour. ENVIRONMENT VARIABLES
The following environment variables affect the execution of sleep: Provides a default value for the internationalization variables that are unset or null. If LANG is unset or null, the corresponding value from the default locale is used. If any of the internationalization vari- ables 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 for- mat and contents of diagnostic messages written to standard error. Determines the location of message catalogues for the processing of LC_MESSAGES. SEE ALSO
Commands: wait(1) Functions: alarm(3), pause(3), sigaction(2), sleep(3) Standards: standards(5) sleep(1)
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