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Getting an "ambiguous redirect" error

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bash

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What is ambiguous output redirect?

The "ambiguous redirect" error sometimes happens if you either have spaces where they shouldn't be, or conversely when an important space is missing. I would simplify your command to demonstrate: echo "Test" >/tmp/x.txt 2>&1 & The ">/tmp/x. txt" part will redirect stdout (file handle #1).

What does it mean to redirect to 2 >& 1?

"You use &1 to reference the value of the file descriptor 1 (stdout). So when you use 2>&1 you are basically saying “Redirect the stderr to the same place we are redirecting the stdout”. And that's why we can do something like this to redirect both stdout and stderr to the same place:"

How do I declare a variable in bash?

A variable in bash is created by assigning a value to its reference. Although the built-in declare statement does not need to be used to explicitly declare a variable in bash, the command is often employed for more advanced variable management tasks.


Bash can be pretty obtuse sometimes.

The following commands all return different error messages for basically the same error:

$ echo hello >
bash: syntax error near unexpected token `newline`

$ echo hello > ${NONEXISTENT}
bash: ${NONEXISTENT}: ambiguous redirect

$ echo hello > "${NONEXISTENT}"
bash: : No such file or directory

Adding quotes around the variable seems to be a good way to deal with the "ambiguous redirect" message: You tend to get a better message when you've made a typing mistake -- and when the error is due to spaces in the filename, using quotes is the fix.


Do you have a variable named OUPUT_RESULTS or is it the more likely OUTPUT_RESULTS?


michael@isolde:~/junk$ ABC=junk.txt
michael@isolde:~/junk$ echo "Booger" > $ABC
michael@isolde:~/junk$ echo "Booger" >> $ABB
bash: $ABB: ambiguous redirect
michael@isolde:~/junk$ 

put quotes around your variable. If it happens to have spaces, it will give you "ambiguous redirect" as well. also check your spelling

echo $AAAA"     "$DDDD"         "$MOL_TAG  >>  "${OUPUT_RESULTS}"

eg of ambiguous redirect

$ var="file with spaces"
$ echo $AAAA"     "$DDDD"         "$MOL_TAG >> ${var}
bash: ${var}: ambiguous redirect
$ echo $AAAA"     "$DDDD"         "$MOL_TAG >> "${var}"
$ cat file\ with\ spaces
aaaa     dddd         mol_tag

I've recently found that blanks in the name of the redirect file will cause the "ambiguous redirect" message.

For example if you redirect to application$(date +%Y%m%d%k%M%S).log and you specify the wrong formatting characters, the redirect will fail before 10 AM for example. If however, you used application$(date +%Y%m%d%H%M%S).log it would succeed. This is because the %k format yields ' 9' for 9AM where %H yields '09' for 9AM.

echo $(date +%Y%m%d%k%M%S) gives 20140626 95138

echo $(date +%Y%m%d%H%M%S) gives 20140626095138

The erroneous date might give something like:

echo "a" > myapp20140626 95138.log

where the following is what would be desired:

echo "a" > myapp20140626095138.log

Does the path specified in ${OUPUT_RESULTS} contain any whitespace characters? If so, you may want to consider using ... >> "${OUPUT_RESULTS}" (using quotes).

(You may also want to consider renaming your variable to ${OUTPUT_RESULTS})