Re: [gentoo-user] [OT] tar exclude syntax tip

[tastytea]

On 2021-05-05 09:33-0400 "Walter Dnes" <waltdnes@××××××××.org> wrote:

>   tar version
>
> ####################################################
> tar (GNU tar) 1.34
> Copyright (C) 2021 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> <https://gnu.org/licenses/gpl.html>. This is free software: you are
> free to change and redistribute it. There is NO WARRANTY, to the
> extent permitted by law.
>
> Written by John Gilmore and Jay Fenlason.
> ####################################################
>
>   I'm passing on this solution to help others avoid my frustration and
> wasted time.  If you've done "RTFM" on tar, you'll find out that "TFM"
> is broken or out-of-date or whatever, re: "--exclude=PATTERN".  I'm
> fighting the urge to turn this into a rant.  Here's my situation...
>
>   I either log in as root or "su -" and then "cd /home".  I want to
> tar up /home/waltdnes, and transfer it to another machine.  While I'm
> at it, I want to exlude directory /home/waltdnes/.cache/ and all *.xz
> files in directory /home/waltdnes/pm/  The "--exclude=" never worked.
>  After much hair pulling, I was ready to give up on the exclude, and
> simply transfer all the unnecessary garbage.
>
>   Then "I asked Mr. Google".  It seems that I wasn't the only person
> running into problems.  After some searching, I finally found a syntax
> that works...
>
> ####################################################
> #!/bin/bash
> export GZIP=-9
> tar cvzf wd.tgz --exclude ".cache/*" --exclude "pm/*.xz" waltdnes
> ####################################################
>
> Notes...
>
> 1) This is obviously not in line with the man page.  Specifically,
> "--exclude" is followed by one space, not an equals sign.
>
> 2) ***THERE MUST BE EXACTLY ONE SPACE BETWEEN EACH WORD***
>
> 3) All directories and/or files to exclude must be listed as relative
> paths to the directory being tarred, i.e. last parameter on the
> command line.
>
> 4) I don't know the maximum line-length, which would limit the number
> of --exclude entries.  In those cases, I wonder if
> "--exclude-from=FILE" works as "--exclude-from FILE".
>

This works fine here with “tar (GNU tar) 1.34”:

$ mkdir -p a/b
$ touch a/file a/b/file
$ touch a/file.xz a/b/file.xz
$ tree a
a
├── b
│   ├── file
│   └── file.xz
├── file
└── file.xz

1 directory, 4 files
$ tar -cvzf test.tar.gz --exclude="a/file" --exclude="a/b/*.xz" a
a/
a/file.xz
a/b/
a/b/file
$ tar -tf test.tar.gz
a/
a/file.xz
a/b/
a/b/file

You can find out the maximum length of the command-line with 
`getconf ARG_MAX`.
-- 
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