如何使用xargs复制名称中包含空格和引号的文件？

Question

I'm trying to copy a bunch of files below a directory and a number of the files have spaces and single-quotes in their names. When I try to string together find and grep with xargs , I get the following error:

find .|grep "FooBar"|xargs -I{} cp "{}" ~/foo/bar
xargs: unterminated quote

Any suggestions for a more robust usage of xargs?

This is on Mac OS X 10.5.3 (Leopard) with BSD xargs .

Answer 1

You can combine all of that into a single find command:

find . -iname "*foobar*" -exec cp -- "{}" ~/foo/bar \;

This will handle filenames and directories with spaces in them. You can use -name to get case-sensitive results.

Note: The -- flag passed to cp prevents it from processing files starting with - as options.

Answer 2

find . -print0 | grep --null 'FooBar' | xargs -0 ...

我不知道grep是否支持--null ，也不知道xargs是否支持-0 ，在Leopard上，但在GNU上它一切都很好。

Answer 3

做原始海报想要的最简单方法是将分隔符从任何空格更改为行尾字符，如下所示：

find whatever ... | xargs -d "\n" cp -t /var/tmp

Answer 4

这样更有效，因为它不会多次运行“cp”：

find -name '*FooBar*' -print0 | xargs -0 cp -t ~/foo/bar

Answer 5

I ran into the same problem. Here's how I solved it:

find . -name '*FoooBar*' | sed 's/.*/"&"/' | xargs cp ~/foo/bar

I used sed to substitute each line of input with the same line, but surrounded by double quotes. From the sed man page, " ...An ampersand (``&'') appearing in the replacement is replaced by the string matching the RE... " -- in this case, .* , the entire line.

This solves the xargs: unterminated quote error.

Answer 6

This method works on Mac OS X v10.7.5 (Lion):

find . | grep FooBar | xargs -I{} cp {} ~/foo/bar

I also tested the exact syntax you posted. That also worked fine on 10.7.5.

Answer 7

Just don't use xargs . It is a neat program but it doesn't go well with find when faced with non trivial cases.

Here is a portable (POSIX) solution, ie one that doesn't require find , xargs or cp GNU specific extensions:

find . -name "*FooBar*" -exec sh -c 'cp -- "$@" ~/foo/bar' sh {} +

Note the ending + instead of the more usual ; .

This solution:

• correctly handles files and directories with embedded spaces, newlines or whatever exotic characters.

• works on any Unix and Linux system, even those not providing the GNU toolkit.

• doesn't use xargs which is a nice and useful program, but requires too much tweaking and non standard features to properly handle find output.

• is also more efficient (read faster ) than the accepted and most if not all of the other answers.

Note also that despite what is stated in some other replies or comments quoting {} is useless (unless you are using the exotic fish shell).

Answer 8

在find中使用带有-print0选项的xargs的--null命令行选项。

Answer 9

对于那些依赖命令的人，除了查找，例如ls ：

find . | grep "FooBar" | tr \\n \\0 | xargs -0 -I{} cp "{}" ~/foo/bar

Answer 10

I have found that the following syntax works well for me.

find /usr/pcapps/ -mount -type f -size +1000000c | perl -lpe ' s{ }{\\ }g ' | xargs ls -l | sort +4nr | head -200

In this example, I am looking for the largest 200 files over 1,000,000 bytes in the filesystem mounted at "/usr/pcapps".

The Perl line-liner between "find" and "xargs" escapes/quotes each blank so "xargs" passes any filename with embedded blanks to "ls" as a single argument.

Answer 11

find | perl -lne 'print quotemeta' | xargs ls -d

I believe that this will work reliably for any character except line-feed (and I suspect that if you've got line-feeds in your filenames, then you've got worse problems than this). It doesn't require GNU findutils, just Perl, so it should work pretty-much anywhere.

Answer 12

Be aware that most of the options discussed in other answers are not standard on platforms that do not use the GNU utilities (Solaris, AIX, HP-UX, for instance). See the POSIX specification for 'standard' xargs behaviour.

I also find the behaviour of xargs whereby it runs the command at least once, even with no input, to be a nuisance.

I wrote my own private version of xargs (xargl) to deal with the problems of spaces in names (only newlines separate - though the 'find ... -print0' and 'xargs -0' combination is pretty neat given that file names cannot contain ASCII NUL '\\0' characters. My xargl isn't as complete as it would need to be to be worth publishing - especially since GNU has facilities that are at least as good.

Answer 13

With Bash (not POSIX) you can use process substitution to get the current line inside a variable. This enables you to use quotes to escape special characters:

while read line ; do cp "$line" ~/bar ; done < <(find . | grep foo)

Answer 14

For me, I was trying to do something a little different. I wanted to copy my .txt files into my tmp folder. The .txt filenames contain spaces and apostrophe characters. This worked on my Mac.

$ find . -type f -name '*.txt' | sed 's/'"'"'/\'"'"'/g' | sed 's/.*/"&"/'  | xargs -I{} cp -v {} ./tmp/

Answer 15

bill_starr's Perl version won't work well for embedded newlines (only copes with spaces). For those on eg Solaris where you don't have the GNU tools, a more complete version might be (using sed)...

find -type f | sed 's/./\\&/g' | xargs grep string_to_find

adjust the find and grep arguments or other commands as you require, but the sed will fix your embedded newlines/spaces/tabs.

Answer 16

If find and xarg versions on your system doesn't support -print0 and -0 switches (for example AIX find and xargs) you can use this terribly looking code:

 find . -name "*foo*" | sed -e "s/'/\\\'/g" -e 's/"/\\"/g' -e 's/ /\\ /g' | xargs cp /your/dest

Here sed will take care of escaping the spaces and quotes for xargs.

Tested on AIX 5.3

Answer 17

I played with this a little, started contemplating modifying xargs, and realised that for the kind of use case we're talking about here, a simple reimplementation in Python is a better idea.

For one thing, having ~80 lines of code for the whole thing means it is easy to figure out what is going on, and if different behaviour is required, you can just hack it into a new script in less time than it takes to get a reply on somewhere like Stack Overflow.

See https://github.com/johnallsup/jda-misc-scripts/blob/master/yargs and https://github.com/johnallsup/jda-misc-scripts/blob/master/zargs.py .

With yargs as written (and Python 3 installed) you can type:

find .|grep "FooBar"|yargs -l 203 cp --after ~/foo/bar

to do the copying 203 files at a time. (Here 203 is just a placeholder, of course, and using a strange number like 203 makes it clear that this number has no other significance.)

If you really want something faster and without the need for Python, take zargs and yargs as prototypes and rewrite in C++ or C.

Answer 18

I used Bill Star's answer slightly modified on Solaris:

find . -mtime +2 | perl -pe 's{^}{\"};s{$}{\"}' > ~/output.file

This will put quotes around each line. I didn't use the '-l' option although it probably would help.

The file list I was going though might have '-', but not newlines. I haven't used the output file with any other commands as I want to review what was found before I just start massively deleting them via xargs.

Answer 19

I created a small portable wrapper script called "xargsL" around "xargs" which addresses most of the problems.

Contrary to xargs, xargsL accepts one pathname per line. The pathnames may contain any character except (obviously) newline or NUL bytes.

No quoting is allowed or supported in the file list - your file names may contain all sorts of whitespace, backslashes, backticks, shell wildcard characters and the like - xargsL will process them as literal characters, no harm done.

As an added bonus feature, xargsL will not run the command once if there is no input!

Note the difference:

$ true | xargs echo no data
no data

$ true | xargsL echo no data # No output

Any arguments given to xargsL will be passed through to xargs.

Here is the "xargsL" POSIX shell script:

 #! /bin/sh # Line-based version of "xargs" (one pathname per line which may contain any # amount of whitespace except for newlines) with the added bonus feature that # it will not execute the command if the input file is empty. # # Version 2018.76.3 # # Copyright (c) 2018 Guenther Brunthaler. All rights reserved. # # This script is free software. # Distribution is permitted under the terms of the GPLv3. set -e trap 'test $? = 0 || echo "$0 failed!" >& 2' 0 if IFS= read -r first then { printf '%s\\n' "$first" cat } | sed 's/./\\\\&/g' | xargs ${1+"$@"} fi 

Put the script into some directory in your $PATH and don't forget to

$ chmod +x xargsL

the script there to make it executable.

Answer 20

您可能需要grep Foobar目录，如：

find . -name "file.ext"| grep "FooBar" | xargs -i cp -p "{}" .

Answer 21

Frame challenge — you're asking how to use xargs. The answer is: you don't use xargs, because you don't need it.

The comment by user80168 describes a way to do this directly with cp, without calling cp for every file:

find . -name '*FooBar*' -exec cp -t /tmp -- {} +

This works because:

• the cp -t flag allows to give the target directory near the beginning of cp , rather than near the end. From man cp :

  -t, --target-directory=DIRECTORY copy all SOURCE arguments into DIRECTORY 

• The -- flag tells cp to interpret everything after as a filename, not a flag, so files starting with - or -- do not confuse cp ; you still need this because the - / -- characters are interpreted by cp , whereas any other special characters are interpreted by the shell.

• The find -exec command {} + variant essentially does the same as xargs. From man find :

  -exec command {} + This variant of the -exec action runs the specified command on the selected files, but the command line is built by appending each selected file name at the end; the total number of invoca‐ matched files. The command line is built in much the same way that xargs builds its command lines. Only one instance of `{}' is allowed within the command, and (when find is being invoked from a shell) it should be quoted (for example, '{}') to protect it from interpretation by shells. The command is executed in the starting directory. If any invocation returns a non-zero value as exit status, then find returns a non-zero exit status. If find encounters an error, this can sometimes cause an immedi‐ ate exit, so some pending commands may not be run at all. This variant of -exec always returns true. 

By using this in find directly, this avoids the need of a pipe or a shell invocation, such that you don't need to worry about any nasty characters in filenames.

Answer 22

If you are using Bash, you can convert stdout to an array of lines by mapfile :

find . | grep "FooBar" | (mapfile -t; cp "${MAPFILE[@]}" ~/foobar)

The benefits are:

• It's built-in, so it's faster.
• Execute the command with all file names in one time, so it's faster.

• You can append other arguments to the file names. For cp , you can also:

   find . -name '*FooBar*' -exec cp -t ~/foobar -- {} + 

  however, some commands don't have such feature.

The disadvantages:

• Maybe not scale well if there are too many file names. (The limit? I don't know, but I had tested with 10 MB list file which includes 10000+ file names with no problem, under Debian)

Well... who knows if Bash is available on OS X?