Use NUL to Sink Program Output

Q

How to use the NUL file name to sink program output?

✍: FYIcenter.com

A

If a program is writing too much out on your screen, you sink all output to the NUL file name.

For example, if you run JMeter program, it will write some output on your screen:

C:\>\fyicenter\jmeter\bin\jmeter > nul

================================================================================

Don't use GUI mode for load testing, only for Test creation and Test debugging !

For load testing, use NON GUI Mode:
   jmeter -n -t [jmx file] -l [results file] -e -o [Path to output folder]
& adapt Java Heap to your test requirements:
   Modify HEAP="-Xms512m -Xmx512m" in the JMeter batch file
================================================================================

12:38:58 AM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0
x80000002. Windows RegCreateKeyEx(...) returned error code 5.

You can redirect STDOUT to NUL by adding "> nul" to the command:

C:\>\fyicenter\jmeter\bin\jmeter > nul

12:40:58 AM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0
x80000002. Windows RegCreateKeyEx(...) returned error code 5.

To remove the error message, you can redirect STDERR to NUL by adding "2> nul" to the command. Now nothing displayed on the screen:

C:\>\fyicenter\jmeter\bin\jmeter > nul 2> nul

 

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2017-12-05, 203👍, 0💬