tar is one of the worst. I think I know what those do without looking it up but I think most people look at that with bewilderment. Randall Munroe is always helpful in these matters and has this to say: https://xkcd.com/1168/
I gave up and added this to my .bashrc:
function extract()
{
if [ -f $1 ] ; then
case $1 in
*.tar.bz2) tar xvjf $1 ;;
*.tar.gz) tar xvzf $1 ;;
*.bz2) bunzip2 $1 ;;
*.rar) unrar x $1 ;;
*.gz) gunzip $1 ;;
*.tar) tar xvf $1 ;;
*.tbz2) tar xvjf $1 ;;
*.tgz) tar xvzf $1 ;;
*.zip) unzip $1 ;;
*.Z) uncompress $1 ;;
*.7z) 7z x $1 ;;
*.zst) zstd -d $1 ;;
*.xz) unxz $1 ;;
*) echo "'$1' cannot be extracted via >extract<" ;;
esac
else
echo "'$1' is not a valid file"
fi
}Another "recent" (much more recent IIRC) change is that you don't need the dot anymore in find to search in the current directory.
extract() {
bsdtar -xf "$1"
}
Anyway, my advice to you and anyone else having trouble with tar is that "tar caf" and "tar xaf" are the only things most people need to remember about tar, with or without compression.
(In this case, most people means people who use tar, but so rarely that they have trouble remembering how to use it; they probably never use it for anything else other than (un)archiving. Also, xkcd isn't gospel.)
Personally, I consciously avoid using the internal decompression features of tar, both out of habit and to avoid unexpected results.
As such, I generally use command lines like: bunzip2 -c <tar.bz2 file> |tar xvf -
instead of relying on tar xvjf
I don't see it as wrong or bad to use tar's decompression features, it's more about my own preferences and experience. Being able to perform similar actions in multiple ways is one of the things I've always appreciated about the shell and the Unix/GNU userland.
tar cf dir.tar dir # mnemonic: 'create file' <tar-file-name> <dir-to-tar>
tar xf dir.tar(.gz|bz2|...) # mnemonic: 'eXtract file' <tar-file-name>
$ tar --help
$ tar --help
tar: unknown option -- help
usage: tar [-]{crtux}[-befhjklmopqvwzHJOPSXZ014578] [archive] [blocksize]
[-C directory] [-T file] [-s replstr] [file ...]
$ $ list '#! /bin/sh' 'echo "tar: invalid command" >&2' 'exit 64' >/tmp/tar
$ chmod a+x /tmp/tar
$ PATH="/tmp:$PATH"
$
$ tar -cf a.tar a/
tar: invalid command
$
Fair enough. My point was that there's a category of operating systems where long options (including --help) isn't really a thing. You may of course consider them defective, though I'm not sure everybody agrees.
Even better. :)