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I run the following file with the > log.log redirector, and it does not capture errors.

#!/bin/bash

echo ************************BEGIN LOG******************************
date +"%m/%d/%Y %H:%M:%S $HOSTNAME"
cp -f /scripts/original/clamscans.log /scripts
find /public/public/clamscans/. -exec grep -n FOUND /dev/null {} \;>>clamscans.log
mail somedude@someplace.com < clamscans.log
tar cvf dailyresults.tar /public/public/clamscans/*.txt
gzip -f dailyresults.tar
mv -f /public/public/clamscans/*.txt /scripts/lastnite
echo end log entry

The following errors show up when I run from the file from the terminal window, but they are not written to log.log:

tar: /public/public/clamscans/*.txt: Cannot stat: No such file or directory
tar: Error exit delayed from previous errors
mv: cannot stat `/public/public/clamscans/*.txt': No such file or directory

What am I doing wrong? I know with Windows you can add the 2>&1 to capture error data. Is there such a thing for Linux?

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migrated from stackoverflow.com Sep 27 '10 at 3:39

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command &> filename to redirect both stdout and stderr to file named filename. –  Michael Foukarakis Sep 24 '10 at 17:10
2  
I think it is Windows that at some point got redirection similar to what is available in the UNIX shell, not vice versa. –  Martin Liversage Sep 24 '10 at 17:13
2  
The funny thing is I had no idea 2>&1 worked on windows, so I thought I read the question wrong at first. Moral of the story: sometimes the equivalent in the other OS is identical. –  Karl Bielefeldt Sep 24 '10 at 17:19

2 Answers 2

up vote 3 down vote accepted

File descriptor 1 is stdout, 2 is stderr. This applies to both Linux and Windows. With ">logfile", you're redirecting stdout to the file "logfile", but what you actually want is to redirect stderr. That can be done with "2>filename" or "2>&1" (in combination with ">logfile") on both Windows and Linux, but note that the order might be significant, so it should be "command >logfile 2>&1" and not the other way round.

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I foolishly assumed it couldn't be that easy. Yet, it works just like Windows. I'm surprised someone didn't flame me for this. Hope I didn't just give somebody an idea either... Thanks. –  micah Sep 24 '10 at 17:20
2  
At least one difference remains, i.e. when you want to discard stderr. With Unix you do 2>/dev/null while with Windows you do 2>nul - unless you're using cygwin or others. –  ott-- Aug 13 '13 at 20:26

You can redirect standard error to a file like this:

mycommand 2> error.log

and you can use the following syntax to redirect both standard output and standard error to a file:

mycommand &> file

or

mycommand > file-name 2>&1
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