Re: [live-build] "E: Unable to find a source package for syslinux,grub-efi"

[jnqnfe@gmail.com]

On Sat, 2020-03-14 at 14:59 +1100, David wrote:
> On Wed, 11 Mar 2020 at 02:39, <jnqnfe@gmail.com> wrote:
> > obviously it seems to be treating "syslinux,grub-efi" as a single
> > package name which is wrong. this string originates from
> > LB_BOOTLOADERS.
> > 
> > the code that should be handling this in source_debian looks to be
> > the
> > following:
> > ```
> > echo "${LB_BOOTLOADERS}" | \
> > while IFS="," read -r BOOTLOADER
> > do
> >         echo "${BOOTLOADER}" >> source-selection.txt
> > done
> > ```
> > 
> > which is correctly specifying a comma as the separator, so if this
> > is
> > where the problem originates, I don't know why...
> 
> If you just need to parse comma-separated tokens from a string,
> then maybe this code will work for you:
> 
> Demo code:
> 
> #!/bin/sh
> s="a1,a2,a3,a4"
> while [ -n "${s}" ] ; do
>     # get $v = leading word of $s, by strip first comma and all
> following
>     v=${s%%,*}
>     # update $s according to $v
>     if [ "${v}" != "${s}" ] ; then
>         # update $s by remove leading $v and a comma from $s
>         s=${s#${v},}
>     else
>         # $v=$s, so nothing was stripped, so nothing more to do
>         s=''
>     fi
>     printf 'v=%s\n' "${v}"
> done
> 
> The above demo code tested produces output:
> v=a1
> v=a2
> v=a3
> v=a4

Thankyou, I appreciate the effort you've put into this but an
explanation of why the existing implementation did not work was
supplied by John Crawley, and I went ahead already with an actual
solution of:
```
for BOOTLOADER in $(echo "${LB_BOOTLOADERS}" | tr "," "\n"); do
	echo "${BOOTLOADER}" >> source-selection.txt
done
```

which is ideally neat and simple, even if it is piping to a binary
rather than achieving the goal within the shell.

your solution on the other hand, whilst I appreciate the effort put
into it, and possibly of interest to people to understand how you
accomplished it, is very much inferior imho considering how big and
complex it is relatively speaking. thank you again though.