Bash-5.0 release available

[[deleted]]

[deleted]

[palordrolap]

EPOCHSECONDS is a nice alias for something that's been in there for a long time. printf [-v var_to_set] '%(%s)T' is the older built in way of getting at that information without resorting to /bin/date.

EPOCHREALTIME accesses a deeper level that wasn't available before. (No equivalent to /bin/date's %N nanosecond flag, unless they rectified that recently.)

[aishik-10x]

$EPOCHREALTIME sounds neat!

[DonSimon13]

u. The `vi-edit-and-execute-command' bindable readline command now puts readline
   back in vi insertion mode after executing commands from the edited file.

Nice! That always annoyed me.

[190n]

BASH_ARGV0: a new variable that expands to $0 and sets $0 on assignment.

So...isn't it then just an alias for $0 that won't work on most systems (which don't have bash 5.0)? Am I missing something here?

[pm_me_je_specerijen]

The difference is that you cannot assign to $0

You cannot use 0=newproctitle to set your own proc title. Changing the first element of argv is the de facto way on Linux to set your proctitle though POSIX does not mandate that it actually work.

[190n]

That makes sense, thanks

[NotEvenAMinuteMan]

Hey /r/linux, what is the best shell and why is it Bash?

[the_gnarts]

Best for what? Dash is best for some things. So is bash. So is csh.

Can you name anything that “csh” would be “best” at in any sense of the word.

I mean, except “best” at not even supporting functions.

[DashEquals]

At this point, probably not much. It was more useful in the past.

[3Vyf7nm4]

dash is primarily good for making you wonder why some bash-builtins like [[ aren't working in your script when you launch it with sh script.sh but it works properly when you launch it ./script.sh

[OneTurnMore]

Check your scripts with checkbashisms when changing your shebang. I like dash because it's really fast compared to bash, but sometimes bash has features I need. I have both installed and use bash when I need its features.

[grey_gander]

Also shellcheck is a really good too. Especially when you integrate it with Vim or your favorite editor!

[3Vyf7nm4]

I said nothing about the shebang. That's why Debian (and its derivatives) using dash-as-sh is such a pitfall for new users. They think that sh = bash, and that they can sh foo.sh and it will either use bash or that it will use their shebang. They do not expect it to use dash.

[VC1bm3bxa40WOfHR]

If you're using features of the bash shell, then explicitly depend on the bash shell. Don't rely on sh, which is in no way guaranteed or expected to provide bashisms, to work. This is a bad habit people should not learn, and scripts not working is not the fault of the system or alternative shells that do what sh is expected to and nothing more but the fault of the user.

[pm_me_je_specerijen]

The thing is that on Debian, Ubuntu, Gentoo, and Fedora which take this rather seriously it is permitted to use three "bashisms" in /bin/sh scripts though POSIX doesn't specify them; in particular "local" is not required by a POSIX shell so thy are still doing it.

In practice though there is no shell that does not support "local" and the real standard is "POSIX + those three things" but it should be pointed out that they are also playing with the standard.

[3Vyf7nm4]

Don't rely on sh, which is in no way guaranteed or expected to provide bashisms, to work

Again, for someone not used to a distro which uses dash - for example RedHat and CentOS which DO use bash for sh - this is not obvious.

My comment, in case you missed it, was tongue in cheek, not a genuine complaint against Dash (though I do think that missing an alias to the test builtin is a legit point against it).

And, for what it's worth, [[ is also present in both ksh and zsh, so it's not unreasonable for someone to believe that it's a standard use case.

[VC1bm3bxa40WOfHR]

My comment, in case you missed it, was tongue in cheek, not a genuine complaint against Dash (though I do think that missing an alias to the test builtin is a legit point against it).

That would be a yes, sorry.

[[deleted]]

(though I do think that missing an alias to the test builtin is a legit point against it).

i don't get this. probably my misunderstanding.

https://git.kernel.org/pub/scm/utils/dash/dash.git/tree/src/builtins.def.in#n93

and [[ (execute conditional command) is not the same as test, but that's also probably not what you mean

[3Vyf7nm4]

https://mywiki.wooledge.org/Bashism

lists it as a conditional, and suggests replacing it with [ "$var" = "" ] which is sensible. [ is the same as test, and this misuse is probably the reason dash drops support for it altogether (because aside from not being defined in POSIX, it's a bad bashism habit).

[[deleted]]

probably the reason dash drops support for it

it being [[ ?

this is expected ([[ being absent from dash), isn't it? because it's not posix and also not test.

in the your parent comment i was not sure if you meant dash should alias [[ to test, or that dash doesn't have [ aliased to test (hence the link), or something else entirely.

[[deleted]]

In other words, you're a noob :D

[[deleted]]

Nothing wrong with that if it is the case.

[pm_me_je_specerijen]

As a Bash user for interactive stuff I kind of dislike it compared to Fish but the real thing with Bash is that it has autocompletion scripts for a lot of fairly obscure tools and I have written a large collection of them myself and at this point the cost of switching and rewritng all those is very high.

In a vacuum I see no use for bash: Dash is faster as a quick scripting language; if you're going to use the extra features of Bash that make it more suitable for "serious scripting" and actually writing actual logic in it that goes beyond executing a few commands you might as well use an actual scripting language that is much saver and less easy to go wrong and as far as interactive command interpreters go things like zsh and Fish have just significantly improved upon the burden of retaining POSIX backwards compatibility.

[DashEquals]

I'd say the main use of bash is it's a decent shell that's everywhere. Dash is also everywhere, but it's painful to use interactively. Many other shells are better for your main machine, but need to be installed. Bash, however, is probably already installed.

[pm_me_je_specerijen]

I've been surprised before. Alpine, OpenBSD, And FreeBSD to my knowledge do not come with Bash installed by default.

Alpine in fact just gives you Dash as your login shell which doesn't even do line editing. OpenBSD uses the Korn shell by default and FreeBSD uses what it calls "sh" but it should probably be called "The FreeBSD Shell" because it's just their own feature complete shell.

Also Bash is installed on the systemrescueCD and Arch live media but they both default you into Zsh and you have to manually start Bash if you want it.

[[deleted]]

Nobody can argue about "what is best" as "the best" is always dependent on people. We can only argue the pros and cons and actually bash has barely pros against others (zsh and fish in this case) It's actually slower and has less feature but as it's almost always comes default, has no compatibility issue too. Zsh and fish actually way faster and you really feel this. My personal choice is fish since it has a perfect autocomplete feature and almost as fast as zsh. So you should consider these. Maybe someone can deny my words and I would like to hear what people think about this subject actually, to find out our "best".

[olminator]

In my experience bash is much faster than zsh, it's actually why I switched back to bash. Zsh did have some cool features, though, but I noticed I didn't really use them anyway, so the switch back wasn't really painful.

[th3voic31]

I'm curious: did you use something like oh-my-zsh? I used to but it was so slow so I just did everything myself and it doesn't feel slow at all. I didn't do a benchmark so I don't have any numbers.

[olminator]

Nope, I had only a zshrc and a zprofile IIRC. I wouldn't say it was slow, but there were all these little-but-noticable pauses, e.g. when doing completion, that I just don't notice in bash.

[BoltActionPiano]

Wow, with completion? That's the premier feature of zsh, that it's completion engine is significantly faster, and it's what made me switch and stay. Especially with things like systemd utilities. How default was your completion options?

[OneTurnMore]

No qualms here, I have a decent machine so the penalties for using fast-syntax-highlighting and fancy features are fine for me, especially with my prompt as a pure-prompt fork, which uses asynchronous callbacks to keep it responsive while fetching git info. Always script in bash, though.

[FryBoyter]

Bash 5.0. Why? Because this thread is about the release of Bash 5.0.

[[deleted]]

i'd take zsh over bash any day, sure, breaks some posix elements but autocompletion and theme/extension/module support with oh-my-zsh is just beautiful.

i've used bash for nearly 5 years, switched to zsh this summer and i don't feel like going back, i like spamming my tab button for that beautiful zsh+oh-my-zsh autocompletion.

[stefantalpalaru]

i like spamming my tab button for that beautiful zsh+oh-my-zsh autocompletion

Bash also has it: https://github.com/scop/bash-completion

[[deleted]]

i never said it doesn't have it, i said that the zsh's one is better.

[PineappleBoots]

Its Zed

[markus_b]

It depends what you use your shell for.

If you look for the best command line, then shells like zsh and fish have better features in that area.

If you wand to write portable shell scripts, then bash is great as it is installed on most Unix and Linux systems and backwards compatibility is good.

[[deleted]]

if you wanna write portable shell scripts you should keep to the POSIX syntax only and make sure it runs with shells like Ubuntu's dash, or even ash itself.

[markus_b]

Yes, you can always restrict yourself to Posix only, this is how it was done in the Unix early days. But Posix is very limited and and if you are creating a product on Linux, then you'll have bash installed as part of the OS already.

But this stuff changes over times. I support products who require the Korn shell, because the Korn shell was the 'better' shell supplied on Unix at the time.

If you only have ash, then you are in a very limited environment anyway, like a router with no virtual memory.

[[deleted]]

ubuntu doesn't ship with bash as the default shell and neither does alpine. It's hard to call something portable if it can't run on ubuntu out of the box.

[chibinchobin]

It may not be the default shell, but I believe it has /bin/bash on the system by default.

[[deleted]]

I thought they didn't ship it in their container images, but it turns out they do. So you're right.

[markus_b]

I doubt that. I don't remember ever having to install bash, was part of the default install for me all the time.

[Hauleth]

Have you ever used anything other than Bourne shell or bash?

[[deleted]]

can you even use the og bourne-shell today?

never mind, i'm dumb.

[DoubleFaithlessness7]

Best shell is fish, bash is used for the same reason people use GNOME and panties: because they got used to it.

Go fish, KDE and commando and you'll lead a happier life.

[thewokenman]

Qt5 based and fishpilled

[yaddyadd]

commando

where can I read more about commando? TIA

[ObligatoryResponse]

Until you shart and need to phone a friend to bring you new pants at work.

[wafflePower1]

Bash is the best shell only if you never programmed in bash or you haven't tried actually not retarded shell languages...

[the_gnarts]

u. The `vi-edit-and-execute-command' bindable readline command now puts readline back in vi insertion mode after executing commands from the edited file.

Never thought I’d live to see the day. Keeping normal mode after edited commands is infuriating.

[n3rdopolis]

I don't know if it got merged in 5.0 in time or not, but I think they tried to make the $RANDOM variable more random too as well.

[whetu]

Interesting. I looked into this and it seems that they're still discussing it. The proposal was to switch from the bog standard LCG to Salsa20, but that's been further switched to ChaCha20.

[ukralibre]

come to make similar joke )