How to use > in an xargs command?

Actually, most of the answers here do not work with all filenames (if they contain double and single quotes), including the answer by lhunath and Stephan202.

This solution works with filenames with single and double quotes:

find . -mindepth 1 -print0 | xargs -0 -I{} sh -c 'grep ABC "$1" > "$1.out"' -- {}

Here's a test with filename with both single and double quotes:

echo ABC > "I'm here.txt"

# lhunath solution (hangs waiting for input)

$ find . -exec sh -c 'grep "$1" > "$1.out"' -- {} \;

# Stephan202 solutions

$ find . -mindepth 1 -maxdepth 1 -type f -exec sh -c "grep ABC '{}' > '{}.out'" \;
grep: ./Im: No such file or directory
grep: here.txt > ./Im here.txt.out: No such file or directory

$ ls -1 | xargs -I {} sh -c "grep ABC '{}' > '{}.out'"
xargs: unterminated quote

# this solution
$ find . -mindepth 1 -print0 | xargs -0 -I{} sh -c 'grep ABC "$1" > "$1.out"' -- {}

$ ls -1
"I'm here.txt"
"I'm here.txt.out"

Do not make the mistake of doing this:

sh -c "grep ABC {} > {}.out"

This will break under a lot of conditions, including funky filenames and is impossible to quote right. Your {} must always be a single completely separate argument to the command to avoid code injection bugs. What you need to do, is this:

xargs -I{} sh -c 'grep ABC "$1" > "$1.out"' -- {}

Applies to xargs as well as find.

By the way, never use xargs without the -0 option (unless for very rare and controlled one-time interactive use where you aren't worried about destroying your data).

Also don't parse ls. Ever. Use globbing or find instead: http://mywiki.wooledge.org/ParsingLs

Use find for everything that needs recursion and a simple loop with a glob for everything else:

find /foo -exec sh -c 'grep "$1" > "$1.out"' -- {} \;

or non-recursive:

for file in *; do grep "$file" > "$file.out"; done

Notice the proper use of quotes.

A solution without xargs is the following:

find . -mindepth 1 -maxdepth 1 -type f -exec sh -c "grep ABC '{}' > '{}.out'" \;

...and the same can be done with xargs, it turns out:

ls -1 | xargs -I {} sh -c "grep ABC '{}' > '{}.out'"

---

Edit: single quotes added after remark by lhunath.

I assume your example is just an example and that you may need > for other things. GNU Parallel http://www.gnu.org/software/parallel/ may be your rescue. It does not need additional quoting as long as your filenames do not contain \n:

ls | parallel "grep ABC {} > {}.out"

If you have filenames with \n in it:

find . -print0 | parallel -0 "grep ABC {} > {}.out"

As an added bonus you get the jobs run in parallel.

Watch the intro videos to learn more: http://pi.dk/1

The 10 seconds installation will try to do a full installation; if that fails, a personal installation; if that fails, a minimal installation:

$ (wget -O - pi.dk/3 || lynx -source pi.dk/3 || curl pi.dk/3/ || \
   fetch -o - http://pi.dk/3 ) > install.sh
$ sha1sum install.sh | grep 883c667e01eed62f975ad28b6d50e22a
12345678 883c667e 01eed62f 975ad28b 6d50e22a
$ md5sum install.sh | grep cc21b4c943fd03e93ae1ae49e28573c0
cc21b4c9 43fd03e9 3ae1ae49 e28573c0
$ sha512sum install.sh | grep da012ec113b49a54e705f86d51e784ebced224fdf
79945d9d 250b42a4 2067bb00 99da012e c113b49a 54e705f8 6d51e784 ebced224
fdff3f52 ca588d64 e75f6033 61bd543f d631f592 2f87ceb2 ab034149 6df84a35
$ bash install.sh

If you need to move it to a server, that does not have GNU Parallel installed, try parallel --embed.