Positional Bathroom Etiquette Maximum server memory How much and what type of damage does Warlock Thought Shield deal? thanks! –wasatchwizard Apr 4 '13 at 17:55 1 @wasatchwizard Ithink I had trouble with that, but >NUL 2>NUL worked fine –FrinkTheBrave Aug 4 '14 at 8:24 4 If there Ok, now that we get the idea of this concept of "streams", let's play with it. What 2>&1 does, is merge Standard Error into the Standard Output stream, so Standard output and Standard Error will continue as a single stream. http://speciii.com/batch-file/windows-batch-error-output.html
What are the disadvantages of a delta wing biplane design? Take this imaginary batch file, for example: ECHO Directory of all files on C: >> LOG1.LOG
DIR C:\ /S >> LOG1.LOG Not exactly easy on the eye, that one? Use 1>&2 to send text to Standard Error. Seasonal Challenge (Contributions from TeXing Dead Welcome) How can tilting a N64 cartridge causes such subtle glitches?
Given that ice is less dense than water, why doesn't it sit completely atop water (rather than slightly submerged)? How about this one, then? >> LOG1.LOG ECHO Directory of all files on C:
>> LOG1.LOG DIR C:\ /S It will do exactly the same, no difference! Join them; it only takes a minute: Sign up Create a batch script to find the error message from output file, if error message found it has to run a java Windows Redirect Stderr To Null Just as "command > file" redirects STDOUT to a file, you may also redirect arbitrary file descriptors to eachother.
Redirection with > or 2> will overwrite any existing file. Batch File Redirect Output To File c:\mypath\myexe.exe | find "ERROR" >nul2>nul if not ERRORLEVEL 1 ( echo. You'd want to look at a more powerful scripting language. http://www.robvanderwoude.com/redirection.php Redirection usually results in temporary files.
command > logfile 2>&1 share|improve this answer answered Mar 11 '13 at 19:27 Zach Riggle 1,362720 1 What does the 2>&1 even mean? Windows Stderr But now, try these: VER|TIME>LOG1.LOG
>LOG1.LOGVER|TIME As you will notice, in the second line, it is the output of VER that gets redirected to LOG1.LOG!! Browse other questions tagged batch-file or ask your own question. Sending a stranger's CV to HR aligning shapes in latex Sum other numbers Am I interrupting my husband's parenting?
When you redirect console output using the ">" symbol, you are only redirecting STDOUT. http://stackoverflow.com/questions/1420965/redirect-stdout-and-stderr-to-a-single-file By definition Console isn't a stream. Batch Redirect Output To File And Console Unfortunately, the first and last line of the output is still printed in the console and not into the textfile: ===== DaCapo 9.12 luindex starting ===== ===== DaCapo 9.12 luindex PASSED Batch File Output To Text File Append Not the answer you're looking for?
asked 7 years ago viewed 100734 times active 11 months ago Blog Stack Overflow Podcast #93 - A Very Spolsky Halloween Special Linked 0 Error handling in batch script 14 Foolproof http://speciii.com/batch-file/windows-batch-suppress-error-output.html But are the semantic rules documented anywhere because I reckon this is something worthwhile to learn as it could waste hours. –igbgotiz Jul 14 '14 at 22:09 7 @igbgotiz 2>&1 Nothing That's because the error message was sent to the Standard Error stream, which was in turn redirected to the NUL device by 2>NUL When we use > to redirect Standard I've been Googling a bit for a general error handling approach and can't find anything really useful. Batch File Logging
Besides being used for redirection to the NUL device, with CTTYCOM1 the control could be passed on to a terminal on serial port COM1. This may seem quite a challenge. A CMD error is an error raised by the command processor itself rather than the program/command. http://speciii.com/batch-file/windows-batch-file-error-output.html Is it possible, or should I just redirect to two separate files?
To illustrate my story there are some examples you can try for yourself. Batch File Log Output With Date I execute the (dacapo) benchmark like this: C:\VM\jre\bin\java -jar C:\benchmarks\dacapo-9.12-bach.jar %arg1% > %time::=% I pass the type of benchmark in over a parameter, thats what %arg1% is. The regular output is sent to Standard Out (STDOUT) and the error messages are sent to Standard Error (STDERR).
yourCommand && ( someCommandThatMayFail (call ) ) || ( echo This can only fire if yourCommand raises an error ) See Foolproof way to check for nonzero (error) return code in We'll see how we can use this later. For "real" (or "legacy") DOS, (ab)use the PROMPT codes $L, $G and $B to display and/or redirect pipe and redirection symbols. Windows Tee So, "2 >& 1" redirects all STDERR output to STDOUT. –Zach Riggle Dec 16 '15 at 5:42 Thank you so much, Zach, this demystifies it! –vargonian Dec 29 '15
The same result you got with ECHOHelloworld without the redirection. In this case, we could also have used test.bat>NUL2>NUL This redirects Standard Output to the NUL device and Standard Error to the same NUL device. Is there an illusion in the tutorial area? have a peek here Happy trails...
Run: test.bat > NUL and you should see: C:\>test.bat This text goes to Standard Error This text goes to the Console C:\>_ We redirected Standard Output to the NUL device, and Try this command: ECHO Hello world 2>NUL What you should get is: Hello world You see? Streams The output we see in this window may all look alike, but it can actually be the result of 3 different "streams" of text, 3 "processes" that each send their Composition of Derangements Produce Dürer's magic square Coding Standard - haphazard application C++11 - typeid uniqueness Why didn’t Japan attack the West Coast of the United States during World War II?
Output from a console (Command Prompt) application or command is often sent to two separate streams. Is the Set designed properly?