Hacker News Reader

Comment by chx | Hacker News Reader

And yet, the top search result is tldp. This is what #bash on freenode has to say about that site:

> The infamous "Advanced" Bash Scripting Guide should be avoided unless you know how to filter out the junk. It will teach you to write bugs, not scripts. In that light, the BashGuide was written: http://mywiki.wooledge.org/BashGuide

Now, that site is on the second "page" of the search results.

View on HN

Do they have examples of how it's bad as opposed to simply declaring it bad?

Well for example, I just skimmed through it and I don't see an explanation of quoting, probably one of the first things I would want to explain, around the time variables are explained. It also has examples like this:

        #!/bin/bash
        for i in $( ls ); do
            echo item: $i
        done

which both uselessly calls ls (you may as well just use a glob) and doesn't work as intended if there are filenames with spaces in the directory.

You also have:

        #!/bin/bash
        for i in `seq 1 10`;
        do
                echo $i
        done

Why is it using backticks here instead of $() as in thr former example? Also, no mention that seq is not available on some systems. And, you should be using bash's sequence expression[1] anyway (added in bash 4.x), so the guide is likely out of date.

1. http://www.gnu.org/software/bash/manual/bashref.html#Brace-E...

I use some systems without seq, and they have Bash with version 2.x or 3.x on them (eg., OSX). seq has the nice property that writing a shell or executable replacement is easy.

I think the 2nd example is fine. It might be cut and pasted from a POSIX example.

Those are fair points. Another nit I just noticed in the second example is the extraneous semicolon.

Using ls instead of a glob can be valid if you need to force ordering for some reason (you want to process things in date order for instance, IIRC the order out of a glob wildcard is alphanumeric in most places and arbitrary in some). Your point about spaces in filenames is definitely valid though but my preferred solution to that would be to stab people with a needle every time they put a space in a filename!

Bah, spaces are perfectly cromulent characters. It's the bourne shell that's broken. rc works fine with them.

There are a great many things on the command line (less elsewhere, but still some) that don't handle spaces in filenames well.

You are probably right that this is a technological fault rather than a problem with spaces themselves, but IMnsHO until we are not regularly using spaces as list item separators using them with the items being listed is asking for issues.

You can easily deal with spaces in bourne shell. Quote your variables. Change the IFS to make it only newlines. Of course, newlines in filenames are perfectly valid too.

Spaces are perfectly okay in a filename. Not that I use them, but this isn't 1990 anymore.

>you should be using bash's sequence expression anyway

I'd love to, but it inexplicably doesn't support variables. You have to hard code the range and step. Pretty much useless for most of my use cases.

The TLDP bash guide is full of a range of submitted examples that run the gamut of good and bad practices. That said, it's still one of the better resources out there, and I have the reference page bookmarked. But this is Bash we're talking about, "best" practice is a relative term.

I'd like that too.

At this stage it's no better than a meme: https://groups.google.com/d/msg/comp.os.linux.misc/w0bcKoEye...

I know that if you mention the TLDP stuff in #bash you get yelled at, though.

To be fair, searching it in Google also gives TLDP pages as the top results. I think TLDP just has better SEO.

It just has more nodes pointing to its links.

That's the danger behind PageRank. If something false is popular enough, it will replace fact.

Not just more nodes, then it would have been easy, but more "credible and relevant" nodes. At least that's the idea.

correct. simple back-links no longer have the weight they used to (and in some situations can actually harm your SEO).

Backlinks must come from other reputable (in google's algorithm's eye's) sites before they carry any weight.

So, this would mean, tldp.org has a lot of top-ranked linux/bash and related sites pointing to it's pages.

Is there any alternative, though? You can't algorithmically determine truth.

Not without sentiment analysis applied to links. However, that's game-able.

I learned bash using tldp years ago, never had any major issues.

Reply on news.ycombinator.com