* Jim Diamond <Jim.Diamond@nonoise.AcadiaU.ca>:
> On 2007-09-26, James Michael Fultz <xyzzy@sent.as.invalid> wrote:
[ ... ]
>> Debian and Ubuntu which is derived from it. dash is the Debian Almquist
>> Shell, a fork of the Almquist Shell (ash) which is also available in
>> Slackware.
> Thanks for the details.

I'm not sure how many other Linux distributions use something else
besides Bash for sh. NetBSD uses ash for '/bin/sh', and last I knew,
so does FreeBSD.

[ Bash-isms in shell scripts ]
> In those cases, such scripts should read #! /bin/bash
> anyway, since the assumption that "sh" == "bash" is a bug.

I agree wholeheartedly. Conversely, I've seen scripts that implicitly
invoke Bash but make no use of Bash's extensions. Unfortunately,
unintended(?) Bash-isms tend to make using another shell from Bash as sh
potentially problematic on Linux systems.

> But one could run all the posix-compatible scripts with some faster
> shell, which still might improve things. (My comments on that in
> another reply here.)

Care would have to be taken with scripts that source others as is the
case with some of Slackware's initscripts.

--
James Michael Fultz <xyzzy@sent.as.invalid>
Remove this part when replying ^^^^^^^^

On Wed, 26 Sep 2007 21:00:50 -0300, Jim Diamond wrote:

> On 2007-09-26, Mark South <mark.south@null.invalid> wrote:
>> On Wed, 26 Sep 2007 12:42:05 +0200, Niki Kovacs wrote:
>>
>>> Jim Diamond a écrit :
>
>>>> I saw an article somewhere the other day saying some distro (Ubuntu
>>>> 7.04 maybe?) has /bin/sh linked to "dash", which is a lightweight
>>>> posix-complaint shell. Reportedly by doing this the boot scripts run
>>>> enough faster that the overall boot was sped up by some large amount
>>>> (45% is a wild guess).
>>
>> Hmmmm. Let's investigate, shall we?
>>
>> (FX: footsteps walking across room away from listener; sounds of laptop
>> keyboard being tapped; there is the occasional curse
> Waiting for it to boot?? :-)

It's normally awake during the day. The cursing is because I am about the
world's second-worst typist.

>>> Boot speed seems a popular item in distro reviews. With all respect, but
>>> I've never cared about boot speed, but much more about: what have I got
>>> once my system has finished booting?
>
>> Put boot speed right there with default colour schemes, choice of default
>> wallpaper, and number of clickable buttons in the installer, then :-)
>
>>> Would you choose your girlfriend by how fast she gets out of bed? )
>
> This has got to be one of the most bizarre (attempted) analogies I've
> seen in a long time.

See the thread in alt.os.linux.ubuntu about mounting disks and where the
analogy with trees gets you :-)

>> Boot speed does make a difference to people who have their flaptops
>> with them at all times, and who don't like to use suspend/resume too
>> many times between reboots (let's face it, there's too much flaky ACPI
>> hardware out there).
> On my current laptops I have managed to beat the ACPI issues pretty much
> into submission, and so normally I S2R and resume. But every now and
> then I have to reboot (I sometimes need to check something out in
> another version of Slackware or even (*cough*) another Linux distro, and
> running it under VMware doesn't always cut it). So yes, boot may only
> be 90 (?) seconds, but 50 would be nicer.

Ideal boot time? Zero seconds, obviously. How much of your life do you
think has been spent waiting for systems to boot?

frz <frzd@hotmail.com> wrote:
> Another question; could a bootable system be just the running kernel
> and a shell?

Yes, that description rather much resembles what a Slackware installation
environment looks like. Instead of using init and inittab to let the user
log in and then start a shell the shell is started directly.

However, to be able to do anything useful in your shell you will also need
other binaries like ls, cp and cat.

regards Henrik
--
The address in the header is only to prevent spam. My real address is:
hc1(at)poolhem.se Examples of addresses which go to spammers:
root@localhost postmaster@localhost

On Fri, 28 Sep 2007 11:16:34 +0200, Henrik Carlqvist wrote:

> frz <frzd@hotmail.com> wrote:
>> Another question; could a bootable system be just the running kernel
>> and a shell?

Essentially, yes, although one needs to have a filesystem in place as well.

And you need enough infrastructure in place to be able to boot the system,
which normally means installing a bootloader somewhere.

> Yes, that description rather much resembles what a Slackware installation
> environment looks like. Instead of using init and inittab to let the user
> log in and then start a shell the shell is started directly.
>
> However, to be able to do anything useful in your shell you will also need
> other binaries like ls, cp and cat.

Here's an educational project for a rainy day that lets one see how small
and simple Linux can be:

http://www.happy-monkey.net/pocket/

It's a Linux system on 2 floppies that you build yourself from source.

Floppies don't need a bootloader either, since the kernel can load itself
from a floppy.

I did this project over the course of a weekend about 3 years ago and
learned quite a bit about how some bits of Linux work.