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I'm trying to redirect all output (stdout + stderr) of a DOS command to a single file:
C:\>dir 1> a.txt 2> a.txt The process cannot access the file because it is being used by another process. Is it possible, or should I just redirect to two separate files?
958
You can redirect stderr to stdout by using 2>&1 , and then pipe stdout into grep . what does &1 means? To specify redirection to existing handles, use the ampersand & character followed by the handle number that you want to redirect (that is, &handle# ).
Understanding the concept of redirections and file descriptors is very important when working on the command line. To redirect stderr and stdout , use the 2>&1 or &> constructs.
On a command line, redirection is the process of using the input/output of a file or command to use it as an input for another file. It is similar but different from pipes, as it allows reading/writing from files instead of only commands. Redirection can be done by using the operators > and >> .
You want:
dir > a.txt 2>&1 The syntax 2>&1 will redirect 2 (stderr) to 1 (stdout). You can also hide messages by redirecting to NUL, more explanation and examples on MSDN.
185
Anders Lindahl's answer is correct, but it should be noted that if you are redirecting stdout to a file and want to redirect stderr as well then you MUST ensure that 2>&1 is specified AFTER the 1> redirect, otherwise it will not work.
REM *** WARNING: THIS WILL NOT REDIRECT STDERR TO STDOUT **** dir 2>&1 > a.txt If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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