Hacker News Reader

Comment by philwelch | Hacker News Reader

This is a crime against usability IMO. Another comment mentioned that tar takes arguments as "target source" rather than "source target".

Ever notice that for everything in the world that screws, like valves or screws or bottle caps, counter-clockwise loosens and clockwise tightens? How is it we got the whole world to agree on that convention, but software is 50/50 on how we order the source and destination?

View on HN

My first car (a 1967 Dodge Monaco) had 'backwards' lug nuts on the left hand side of the car...

http://en.wikipedia.org/wiki/Lug_nut#History

Propane tanks also used to have backwards screwing connections. I believe this was a safety 'feature' given the mainstream use of small propane tanks. Having them tighten counter-clockwise prevents similar looking but wrong hoses from being attached to the tank. It also tricked people who didn't understand propane tanks form being able to remove a connection (since they would usually just tighten it further).

Cars generally still do have backwards nuts on the LHS. Something about vibration and direction of turn. Some of the other bolts on the LHS can be that way too.

Same with some of the LP gas cylinders I have encountered here in Aus.

Nah. I used to change tyres for a living and I never came across a car with backwards nuts on either side.

I have heard that other manufacturers originally starting using reverse-thread propane fittings to work around a 1896 Primus patent, and the situation has simply persisted.

tar is like that because of command lines

tar [args] [one thing] [list of things]

it'd be wierd if it was

tar [args] [list of things] [filename]

... but i will admit i frequently make that mistake.

But, as a counterpoint, if you want to copy several things to a folder, you do:

  cp [args] [list of things] [destination folder]

But you can also do

  cp [args] -t [destination folder] [list of things]

The same is true of mv. This is useful if you are piping filenames to xargs.

Thanks! I always wondered what was the purpose of -t. Never occurred to me it was to allow you to reverse the order of args.

tar is actually

  tar [args] [list of things]

where [args] may contain [-f filename], among other things.

That is, the destination filename is an optional argument; by default tar outputs to a tape device or stdout, depending on the implementation.

At least in GNU tar, the target filename can very well be specified as the last argument:

  tar -c foo.txt bar.txt baz.txt -f stuff.tar

good point!

I don't feel it's a crime. For that matter, I don't even prefer one over the other.

For "mv A B"

I've no problem saying either

  mv into A the contents of B

  mv the contents of A into B

Who does prefer one over the other? The lack of consistency is the real problem.

Except volume dials.

And sometimes doorknobs, but those are abstract enough you wouldn't expect them to behave the same. Unless you're talking about screwing the dial itself clean off.

And gas valves.

I conclude from this, by process of logical inference, that "louder" must be a type of "tighter".

"Forward" is also "tighter", apparently.

Reply on news.ycombinator.com