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Sleep random seconds in programming | Sleep random seconds in programming | ||
== MS-DOS == | == MS-DOS on Windows == | ||
=== Approach 1: %RANDOM% + ping local === | === Approach 1: %RANDOM% + ping local === | ||
[https://stackoverflow.com/questions/8258087/bat-random-timeout batch file - .bat random timeout - Stack Overflow] | [https://stackoverflow.com/questions/8258087/bat-random-timeout batch file - .bat random timeout - Stack Overflow] |
Revision as of 11:10, 14 October 2021
Sleep random seconds in programming
MS-DOS on Windows
Approach 1: %RANDOM% + ping local
batch file - .bat random timeout - Stack Overflow
- %RANDOM% returns an integer between 0 and 32767.
- 60 is the range of values you want: 0 to 60.
- 32768 is the range of values returned by %RANDOM% (0 to 32767).
- 5 is the minimum value you want. The original range of values you want '0 to 60' became '5 ~ 65'.
- ping local address: /n <Count> "Specifies the number of echo Request messages sent. The default is 4."[1][2]
BAT file:
REM print current date & time ECHO %date% %time% REM sleep 5 ~ 65 seconds SET /a timeout=%RANDOM% * 60 / 32768 + 5 ping 127.0.0.1 -n %timeout% > nul REM print current date & time ECHO %date% %time%
Approach 2: sleep package of CygWin
Requirement: Install Cygwin on Win & install sleep package (How-to: Setting Up Cygwin/X)
Verify the installation of sleep package[3][4]
- Key-in cmd to open command prompt (How to Open Command Prompt (Windows 10, 8, 7, Vista, XP))
- Key-in one of following commands
- Key-in where sleep if you add installation path of CygWin to system path (How to setup my system path). Or
- Key-in dir C:\cygwin64\bin\sleep.exe if the installation path of CygWin is C:\cygwin64\.
C:\Users\user>dir C:\cygwin64\bin\sleep.exe # successful condition C:\cygwin64\bin\sleep.exe # failed condition File Not Found
BAT file:
REM print current date & time ECHO %date% %time% REM sleep 5 ~ 65 seconds SET /a timeout=%RANDOM% * 60 / 32768 + 5 C:\cygwin64\bin\sleep.exe %timeout% REM print current date & time ECHO %date% %time%
Approach 3: TIMEOUT
Alternative command: The following command ECHO %date% %time% will not be executed after TIMEOUT %timeout% was executed.
BAT file:
SET /a timeout=%RANDOM% * 60 / 32768 + 5 TIMEOUT %timeout% ECHO %date% %time%
BASH
Approach1: sleep
# print current date & time echo $(date '+%Y-%m-%d %H:%M:%S') # sleep 5 ~ 65 seconds timeout=$(($RANDOM * 60 / 32768 + 5)) sleep $timeout # print current date & time echo $(date '+%Y-%m-%d %H:%M:%S')
Sleep couple microseconds[7]. Tested on Linux
# print current unix timestamp e.g. 1598346362244 date +%s%N # sleep 1 millisecond = 0.001 seconds sleep 0.001s # print current unix timestamp date +%s%N
Sleep couple microseconds. Tested on Mac
# print current unix timestamp e.g. 1598346362244 php -r 'echo microtime(TRUE) . PHP_EOL;' # sleep 1 millisecond = 0.001 seconds sleep 0.001s # print current unix timestamp php -r 'echo microtime(TRUE) . PHP_EOL;'
Approach2: ping
ping local address: -c <Count> "Stop after sending (and receiving) count ECHO_RESPONSE packets."[8]
# print current date & time echo $(date '+%Y-%m-%d %H:%M:%S') # sleep 5 ~ 65 seconds timeout=$(($RANDOM * 60 / 32768 + 5)) ping 127.0.0.1 -c $timeout > nul # print current date & time echo $(date '+%Y-%m-%d %H:%M:%S')
Approach3: usleep
usleep(3) - Linux man page "suspend execution for microsecond intervals" (1 second = 1 000 000 microsecond). Tested on Linux
# print current date, time & nanoseconds echo $(date '+%Y-%m-%d %H:%M:%S')$(date '+.%N') # sleep 0.2 ~ 1.2 seconds timeout=$(($RANDOM * 1000000 / 32768 + 200000)) echo $timeout usleep $timeout # print current date, time & nanoseconds echo $(date '+%Y-%m-%d %H:%M:%S')$(date '+.%N')
PHP
JavaScript
References
- ↑ time
- ↑ windows xp - How to wait in a batch script? - Stack Overflow
- ↑ How do I install cygwin components from the command line? - Stack Overflow
- ↑ SLEEP man page on Cygwin
- ↑ Perform arithmetic operations - Linux Shell Scripting Tutorial - A Beginner's handbook
- ↑ Linux Sleep Command (Pause a Bash Script) | Linuxize
- ↑ How do I get the current Unix time in milliseconds in Bash? - Server Fault
- ↑ ping(8) - Linux man page