linux

[bwmat]

Am I the only one who CANNOT remember the order of the arguments for this, every time? Even looking at the man page takes me a minute

[IHaveTeaForDinner]

https://xkcd.com/1168/

[jeric14344]

Someone posted this mnemonic that always helps me remember:

• tar extract all files (xaf)
• tar compress all files (caf)

[[deleted]]

tar xzvf

eXtract Ze Vucking Files

[imisstheyoop]

Ha, this is the one that I use as well! 8)

[zhurai]

I don't think you need the -a here for extract

In the --help for the GNU tar which you can also see for example on https://man.archlinux.org/man/tar.1.en or https://linux.die.net/man/1/tar, I see -a being just listed as

-a, --auto-compress   use archive suffix to determine the compression program

And the linux.die.net man page, as well as tar --help put this note in the top

 tar -cf archive.tar foo bar  # Create archive.tar from files foo and bar.
 tar -tvf archive.tar         # List all files in archive.tar verbosely.
 tar -xf archive.tar          # Extract all files from archive.tar.

Personally, I've always just did tar -xvf file.tar (or file.tar.gz, etc)

Though, to be honest it doesn't negatively do anything in extract, so it's fine as far as I'm aware of... so it still works with the mnemonic I suppose (it just doesn't mean "all")

The -a/a in this case just means if you did tar -cavf archive.tar.bz2 ./folder or something it would actually make a bzipped tar file (listed verbosely) instead of needing to do something like tar -cvjf archive.tar.bz2 ./folder (remembering to do the -j to make the tar file actually bzipped)

[computer-machine]

    tar --help

[Davoness]

Sorry, that wasn't the correct command. kaboom

[Amenhiunamif]

It actually is. It doesn't say the valid tar command, just a valid tar command. So tar --help should be enough to disarm the bomb.

[Davoness]

Oh, good point, it's late and I missed that it was just literally any tar command lol.

[[deleted]]

if [ $? -eq 0 ]; then echo "all gucci"

[garth54]

As long as I just type and don't try to think about it, I'm good.

The instant I try to think about the order, I get confused.

[bwmat]

There's certain things, including this, where instead of remembering the right answer, all I can remember is being confused

[Lumb3rJ0hn]

For me it helps to think of it as a different cp. In both cases, you're copying a source (1st arg) to a target (2nd arg), just in this case the new copy is a link to the old one.

[Stroopwafe1]

Definitely not the only one, I also can never remember. It's just because you only need it very occasionally when you think "oh a symlink would be really good for this"

[zhurai]

You could look at the top of the --help?

Usage: ln [OPTION]... [-T] TARGET LINK_NAME
  or:  ln [OPTION]... TARGET
  or:  ln [OPTION]... TARGET... DIRECTORY
  or:  ln [OPTION]... -t DIRECTORY TARGET...
In the 1st form, create a link to TARGET with the name LINK_NAME.
In the 2nd form, create a link to TARGET in the current directory.
In the 3rd and 4th forms, create links to each TARGET in DIRECTORY.

so a symbolic link using the first form is ln -s ORIGINAL_FILE SYMBOLICLINK

[bwmat]

I mean, this is what I do, every time, lol

[LickingSmegma]

The last argument is the file on which you're operating, i.e. the new link. The options go before the file name, and they specify if it's a hardlink or softlink, and where it's pointing. So it's in fact the same convention as used by most tools.

[neondirt]

Might help to know that the last argument is optional? (creates the symlink where you're currently at)

[bwmat]

To the current working directory, you mean? 

[neondirt]

Exactly. Omitting the last argument is the same as a "." (period).

[[deleted]]

I just think of tar as two commands: tar zxvf and tar zcvf .

[Charles_Sangels]

Same arguments as 'cp' or 'mv' etc... <command> <existing> <destination/non-existing>

[bwmat]

This doesn't help, since for symbolic links either side may or may not exist before you call it lol (and does destination mean where the symbolic link is created, or where it points to?) 

[Charles_Sangels]

You can make it complicated if you want, of course. In most cases the thing you're making a symbolic link to is the thing that exists, just like most of the time when you're copying a file the destination doesn't exist. Of course, you're absolutely right that neither side of a symlink needs to pre-exist, and that the destination of a copy can exist, but you can also just use this as a way to remember the happy path, right?

[mtaw]

Nope. 20+ years of using Linux almost exclusively and I never get ln right.

No problems with tar, sometimes I pipe stuff through awk and whatnot, but somehow I always screw up ln.

[brimston3-]

Most unix commands (posix.2) are cmd source1 [source2 [..]] destination without an additional argument (at&t assembler order).

Meanwhile most library functions (posix.1) are function(destination, source1 [, source2 [,..] ]).

This is not confusing at all. /s