Why does xargs strip quotes from input?

Question

Why does xargs strip quotes from input text?

Here is a simplified example:

echo "/Place/='http://www.google.com'" | xargs echo

outputs

/Place/=http://www.google.com

Is there any way to work-around this? (xargs -0 doesn't help me)

`xargs` treats quotes and backslashes specially as part of the [spec](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/xargs.html). Post what you are trying to do with `xargs` instead. — jw013, May 08 '12 at 13:31

score 38 · Answer 1 · edited May 11 '17 at 12:36

if you want xargs to ignore quotes one of the good soultion can be the use of xargs flag xargs -0

Directly from Man page OPTIONS

OPTIONS -0, --null

Input items are terminated by a null character instead of by whitespace, and the quotes and backslash are not special (every character is taken literally). Disables the end of file string, which is treated like any other argument. Useful when input items might contain white space, quote marks, or backslashes. The GNU find -print0 option produces input suitable for this mode.

I've checked on a GNU system that setting the delimiter to a specific value (like a newline) with -d option (and not just -0) would also cause xargs not to treat the quotes etc specially:

-bash-4.3$ { echo "a'b'c"; echo d; } | xargs -d$'\n' echo
a'b'c d
-bash-4.3$ rpm -qf "$(which xargs)"
findutils-4.6.0.0.99.11a05-alt1.x86_64
-bash-4.3$ { echo "a'b'c"; echo d; } | xargs echo
abc d
-bash-4.3$

This answer suggests using `-0` but goes ahead to given an example using `-d` instead. `-d` as called out by the other answers works on GNU only, and `-0` only works if the input can be provided with a NUL delimiter. — cburgmer, Jul 01 '20 at 12:00

fungusakafungus · Answer 2 · 2021-10-14T09:54:01.140

28

For GNU xargs, I found another solution in the manpage: explicitly specify delimiter to be '\n'. This turns off special handling for quotes:

--delimiter=delim, -d delim

Input items are terminated by the specified character. The specified delimiter may be a single character, a C-style character escape such as \n, or an octal or hexadecimal escape code. Octal and hexadecimal escape codes are understood as for the printf command. Multibyte characters are not supported. When processing the input, quotes and backslash are not special; every character in the input is taken literally.

So,

echo "/Place/='http://www.google.com'" | xargs -d'\n' echo

outputs

/Place/='http://www.google.com'

edited Oct 14 '21 at 09:54

answered Dec 05 '17 at 16:51

fungusakafungus

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Note that it implies GNU `xargs` or compatible – Stéphane Chazelas Dec 05 '17 at 17:20
Also note that it also stops space and tab from being recognised as delimiters (probably just as well in the OP's case). – Stéphane Chazelas Dec 05 '17 at 17:22
[Balman gave a similar solution](/a/361330) (well [actually @imz](/revisions/361330/3)) though yours is somewhat better in that it avoids the use of the `ksh93` `$'...'` quoting operator that is not found in every shell implementation. – Stéphane Chazelas Dec 05 '17 at 17:24
1

I found this helpful again, but I cannot upvote again... – Graham Malmgren Jan 15 '21 at 15:37

score 19 · Accepted Answer · edited Apr 08 '13 at 15:52

19

From the xargs manual:

If you want an input argument to contain blanks or horizontal tabs, enclose it in double quotes or apostrophes. If the argument contains a double quote character ("), you must enclose the argument in apostrophes. Conversely, if the argument contains an apostrophe ('), you must enclose the argument in double quotes. You can also put a backslash (\) in front of a character to tell xargs to ignore any special meaning the character may have (for example, white space characters, or quotes).

This means you can escape quotes if the quotes are quoted themselves:

$ echo "/Place/=\'http://www.google.com\'" | xargs echo
/Place/='http://www.google.com'

will work but echo /Place/=\'http://www.google.com\' | xargs echo will not.

edited Apr 08 '13 at 15:52

vonbrand

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answered May 08 '12 at 13:53

Matteo

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Nothing against down votes but a comment on the reason would help :-) – Matteo Apr 20 '15 at 05:35
3

What if you're piping in input? If I have a script that outputs `"/Place/='http://www.google.com'"`, how can I properly escape it? – Roger Filmyer Jul 07 '15 at 21:19
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@RogerFilmyer your_script | parallel --shellquote | ... – Ole Tange Apr 18 '16 at 12:40

score 10 · Answer 4 · answered May 09 '12 at 14:47

10

You could use GNU Parallel instead:

$ echo "/Place/='http://www.google.com'" | parallel echo
/Place/='http://www.google.com'

Then you do not have to do the quoting yourself.

Learn more: https://www.youtube.com/playlist?list=PL284C9FF2488BC6D1

answered May 09 '12 at 14:47

Ole Tange

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score 8 · Answer 5 · edited May 30 '19 at 11:40

8

I found another solution here https://stackoverflow.com/a/17468560/1795821 that suggests using sed to escape quotes.

For example:

sh-3.2$ echo "/Place/='http://www.google.com'" | sed "s/\'/\\\'/g" | xargs echo
/Place/='http://www.google.com'

edited May 30 '19 at 11:40

fra-san

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answered Dec 10 '16 at 16:14

Kristofor Carle

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Why does xargs strip quotes from input?

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