cp after xargs not working

Question

I run debian jessie on Host 64-bit and in virtualbox 32-bit. To spare traffic I try to cp the i386 packages from host to the shared folder, for using them in virualbox.

My Hostname/var/cache/apt/archives$ ls -al /var/cache/apt/archives/ |
    grep 'i386' | 
    awk '{print $9}'
alsa-oss_1.0.28-1_i386.deb
gcc-4.9-base_4.9.2-10_i386.deb
i965-va-driver_1.4.1-2_i386.deb
libaacplus2_2.0.2-dmo2_i386.deb
libaio1_0.3.110-1_i386.deb
libasound2_1.0.28-1_i386.deb
libasound2-dev_1.0.28-1_i386.deb
libasound2-plugins_1.0.28-1+b1_i386.deb

Shows me the packages I'm looking for. but them I try to cp them after xargs

My Hostname/var/cache/apt/archives$ ls -al /var/cache/apt/archives/ |
    grep 'i386' |
    awk '{print $9}' |
    LANG=C xargs cp -u /home/alex/debian-share/apt-archives/
cp: target 'zlib1g_1%3a1.2.8.dfsg-2+b1_i386.deb' is not a directory

I can not figure out what I am doing wrong. Is this way even possible?

My problem is I can not script. Probable it is somthing like that

for i in *_i386.deb ; do cp [option] full-path to shared-folder

I didn't dry, because I will not mess my Host.

Solution 1

ls -al /var/cache/apt/archives/ |
    grep 'i386' | 
    awk '{print $9}'

can be simplified to /var/cache/apt/archives/*i386*

So, use either of these two:

cp -u /var/cache/apt/archives/*i386* /home/alex/debian-share/apt-archives/

cp -ut /home/alex/debian-share/apt-archives/ /var/cache/apt/archives/*i386*

where

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

See also info on parsing ls

Solution 2

While you already know how you should solve your current problem, I'll still answer about xargs.

xargs puts the string it got in the end of command, while in your case you need that string before the last argument of cp. Use -I option of xargs to construct the command. Like this:

ls /source/path/*pattern* | xargs -I{} cp -u {} /destination/path

In this example I'm using {} to as a replacement string, so the syntax looks similar to find.

Comments

[Admin]

I think you meant to use cp -t instead of cp -u ?

[Admin]

No I mean -u -u, --update copy only when the SOURCE file is newer than the destination file or when the destination file is missing

[Admin]

also, whole thing can be simplified I feel.. something like cp -ut /home/alex/debian-share/apt-archives/ /var/cache/apt/archives/*i386* .. please try this on some other sample directories

[Admin]

That works. I'm thinkinng sometimes to complicated. ^^ Make your comment to an answer, so I can except this.

[Nicholas Terry]

is the {} arbitrary? could I do -Iblah for example?

[aragaer]

Yes, you could.

[Mohamed Sylla]

on mac without -u