Skip to main content
Unix & Linux

Return to Answer

added 1 characters in body
Source Link
mikeserv
mikeserv
  • 59.4k
  • 10
  • 122
  • 242

I use 7 distintdistinct arguments combined between my two tar processes here. The most important one is listed here first:

-x extract - after tar changes to our target directory and receives our renaming instructions we instruct it to begin extracting all of the files into its current directory from the -f - |pipe archive file. No mystery.

I use 7 distint arguments combined between my two tar processes here. The most important one is listed here first:

-x extract - after tar changes to our target directory and receives our renaming instructions we instruct to begin extracting all of the files into its current directory from the -f - |pipe archive file. No mystery.

I use 7 distinct arguments combined between my two tar processes here. The most important one is listed here first:

-x extract - after tar changes to our target directory and receives our renaming instructions we instruct it to begin extracting all of the files into its current directory from the -f - |pipe archive file. No mystery.

added 1441 characters in body
Source Link
mikeserv
mikeserv
  • 59.4k
  • 10
  • 122
  • 242

###ARGUMENTS

I use 7 distint arguments combined between my two tar processes here. The most important one is listed here first:

- stdout/stdin - this informs tar that it will be streaming either its input or output to or from stdin/stdout which it will interpret correctly depending on whether or not it is building or extracting an archive.

-c create - this tells tar to build the archive. The next argument tar expects is...

-f file - we specify that tar will be working with a file object rather than a tape-device or whatever. And the file it will be working with, as noted above, is stdin/stdout - in other words, our |pipe.

./* all $PWD/files - not too much to explain here except that the archive argument comes first, so - then ./*.

...and on the other side of the |pipe...

-C change directory - this informs tar that it needs to change to the directory I specify before performing any other action, so effectively it just cd ../test2 before extraction.

--transform='s/ed/EXPR/' - as has already been mentioned, this did the renaming. But the docs indicate that it can take any sed expression or //flag.

-x extract - after tar changes to our target directory and receives our renaming instructions we instruct to begin extracting all of the files into its current directory from the -f - |pipe archive file. No mystery.

###ARGUMENTS

I use 7 distint arguments combined between my two tar processes here. The most important one is listed here first:

- stdout/stdin - this informs tar that it will be streaming either its input or output to or from stdin/stdout which it will interpret correctly depending on whether or not it is building or extracting an archive.

-c create - this tells tar to build the archive. The next argument tar expects is...

-f file - we specify that tar will be working with a file object rather than a tape-device or whatever. And the file it will be working with, as noted above, is stdin/stdout - in other words, our |pipe.

./* all $PWD/files - not too much to explain here except that the archive argument comes first, so - then ./*.

...and on the other side of the |pipe...

-C change directory - this informs tar that it needs to change to the directory I specify before performing any other action, so effectively it just cd ../test2 before extraction.

--transform='s/ed/EXPR/' - as has already been mentioned, this did the renaming. But the docs indicate that it can take any sed expression or //flag.

-x extract - after tar changes to our target directory and receives our renaming instructions we instruct to begin extracting all of the files into its current directory from the -f - |pipe archive file. No mystery.

Source Link
mikeserv
mikeserv
  • 59.4k
  • 10
  • 122
  • 242

tar will do this for you really fast.

###TEST

First I created 2 directories and 10 files:

% mkdir test1 test2 ; cd test1
% for n in `seq 1 10` ; do touch ABC.file$n ; done
% ls

> ABC.file1   ABC.file2  ABC.file4  ABC.file6  ABC.file8
> ABC.file10  ABC.file3  ABC.file5  ABC.file7  ABC.file9

Then I copied them:

% tar -cf - ./* |\ 
    tar -C../test2 --transform='s/ABC/DEF/' -xf -
% ls ../test2

> DEF.file1   DEF.file2  DEF.file4  DEF.file6  DEF.file8
> DEF.file10  DEF.file3  DEF.file5  DEF.file7  DEF.file9

###TRANSFORM

So GNU tar will accept a sed --transform=EXPRESSION for file renaming. This can even rename only some of the files. For instance:

% tar -cf - ./* |\ 
    tar -C../test2 --transform='s/ABC\(.*[0-5]\)/DEF\1/' -xf -
% ls ../test2

> ABC.file6  ABC.file8  DEF.file1   DEF.file2  DEF.file4
> ABC.file7  ABC.file9  DEF.file10  DEF.file3  DEF.file5

So that's one advantage.

###STREAM

Also consider that this is only two tar processes - and that will not alter regardless of your file count.

tar | tar

tar is as optimized as you could want it to be. This will never have problem argument counts or runaway child processes. This is just A > B done.