This is known as “piping” output to another program, and not suprisingly we use the pipe character | to get the job done. SomeCommand.exe > temp.txt OtherCommand.exe >> temp.txt By default, the > and >> operators redirect stdout. Much better, isn't it? Redirection from a device is not always possible. (2) Redirection to the NUL device is often used to hide standard output, instead of displaying it on screen: COPY *.* A: have a peek at this web-site
If the > operator is escaped, everything should work: start 1st.py arg1 arg2 ^> out.txt (If you want to redirect stderr as well, use 2^> for it.) share|improve this answer edited Note: Be careful when using workarounds like these, they may be broken in future (or even past) Windows versions. This will only work in OS/2 and NT, not in MS-DOS. I'm a software developer loving life in Charlotte, NC, an (ISC)2 CSSLP and an avid fan of Crossfit. http://www.robvanderwoude.com/battech_redirection.php
A workaround that may look a bit intimidating is grouping the command line and escaping the redirection: START CMD.EXE /C ^(command ^> logfile^) What this does is turn the part between Achieve same random number sequence on different OS with same seed Why didn’t Japan attack the West Coast of the United States during World War II? Composition of Derangements How common is it to use the word 'bitch' for a female dog?
What are the alternatives to compound interest for a Muslim? Contact Failed Mail Donate Redirection Redirection command > file Write standard output of command to file command 1> file Write standard output of command to file (same as previous) command Is there any way to bring an egg to its natural state (not boiled) after you cook it? Windows Tee Output 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?
I need to wait 12 minutes to accept the answer though (serverfault requirement)! –Alec Gorge Apr 16 '10 at 3:22 5 This only redirects stdout. Windows Redirect Stderr To Stdout And some, not many, commands send their output to the screen bypassing Standard Output and Standard Error, they use the Console. The general idea was this: CTTY NUL ECHO Echo whatever you want, it won't be displayed on screen no matter what. get redirected here When you are done typing, hit CTRL+Z, which sends the end-of-file (EOF) character.
This could be useful when prompting for input even if the batch file's output is being redirected to a file. Windows Echo To Stderr share|improve this answer edited Jul 22 at 10:38 Tshepang 346212 answered Jul 29 '15 at 16:37 AirCombat 515319 1 Command Prompt is cmd.exe. '> null' creates a file called 'null' Here is an example of emulating the Unix command sleep by calling ping against the loopback address. ECHO I suppose that's why CTTY is no longer available on Windows systems.
windows command-line cmd pipe share|improve this question edited Oct 9 '15 at 19:39 Peter Mortensen 10.3k1369107 asked Sep 14 '09 at 11:20 ripper234 67.3k172467750 3 TechNet: Using command redirection operators a fantastic read Why is the size of my email about a third bigger than the size of its attached files? Windows Command Line Redirect Output To File And Screen Does a long flight on a jet provide a headstart to altitude acclimatisation? Windows Stderr The result will be an empty logfile.
That's because >NUL redirects all Standard Output to the NUL device, which does nothing but discard it. Check This Out Besides being used for redirection to the NUL device, with CTTYCOM1 the control could be passed on to a terminal on serial port COM1. From my Windows help, I searched on redirection (URL ms-its:C:\WINDOWS\Help\ntcmds.chm::/redirection.htm). REM *** WARNING: THIS WILL NOT REDIRECT STDERR TO STDOUT **** dir 2>&1 > a.txt share|improve this answer edited Oct 9 '15 at 19:40 Peter Mortensen 10.3k1369107 answered May 23 '13 Windows Redirect Stderr To Null
share|improve this answer edited Oct 9 '15 at 19:40 Peter Mortensen 10.3k1369107 answered Sep 14 '09 at 11:27 ericp 4401915 add a comment| Your Answer draft saved draft discarded Sign I can assure you I did try! A sample of these differences is shown on the DATE/TIME page. (6) Sometimes we need redirection to create a temporary batch file that uses redirection itself. Source So the interpretation of the parenthesis and redirection is delayed, or deferred.
Are basis vectors imaginary in special relativity? Batch File Output To Text File Append 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 When to ignore errors that are common and the program recovers from How do I disable or lock lookup fields on a Visual Force page?
However, unlike files, devices will never be closed until reboot. asked 6 years ago viewed 13735 times active 3 months ago Blog Stack Overflow Podcast #93 - A Very Spolsky Halloween Special Visit Chat Related 282Useful Command-line Commands on Windows0How to It will only do what it is supposed to do when placed at the end of the command line (as Jennie Walker pointed out to me) or right before the next Redirect Batch File Output To Text File Why mention town and country of equipment manufacturer?
The maximum number of consecutive pipes is 2042 Examples: DIR >MyFileListing.txt DIR /o:n >"Another list of Files.txt" DIR C:\ >List_of_C.txt 2>errorlog.txt DIR C:\ >List_of_C.txt & DIR D:\ >List_of_D.txt ECHO y| DEL Use 1>&2 to send text to Standard Error. For example, you can write a listing of the current directory to a text file: DIR > temp.txt The > operator will overwrite the contents of temp.txt with stdout from the http://speciii.com/output-to/windows-error-output-redirection.html 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.
For an overview of redirection and piping, view my original redirection page. In Windows NT4, early Windows 2000 versions, and OS/2 there used to be some ambiguity with ECHOed lines ending with a 1 or 2, immediately followed by a >: ECHO Hello Reverse Lookup: getting keys from values "/usr/bin/ping" is shown as yellow-on-red in the default Fedora bash color scheme -- what does it mean? Use >CON to send text to the screen, no matter what, even if the batch file's output is redirected.
The regular output is sent to Standard Out (STDOUT) and the error messages are sent to Standard Error (STDERR). Disproving Euler proposition by brute force in C Using "están" vs "estás" when refering to "you" Why cast an A-lister for Groot? But the next one is new: test.bat > NUL 2>&1 and you should see: C:\>test.bat This text goes to the Console C:\>_ This time we redirected both Standard Output and Standard Stdin is file 0, stdout is file 1, and stderr is file 2.
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! This may seem quite a challenge. DIR SomeFile.txt > output.txt 2>&1 To use the contents of a file as the input to a program, instead of typing the input from the keyboard, use the < operator. That's because >NUL redirects all Standard Output to the NUL device, which does nothing but discard it.
Using "." in layers name Is there any way to bring an egg to its natural state (not boiled) after you cook it? Ok, now that we get the idea of this concept of "streams", let's play with it. From http://support.microsoft.com/kb/110930: When redirecting output from an application using the ">" symbol, error messages still print to the screen.