Re: [gentoo-dev] [New eclass] twisted-r1.eclass

[Michał Górny]

Dnia 2013-08-03, o godz. 15:37:54
Alex Xu <alex_y_xu@×××××.ca> napisał(a):

> On 03/08/13 02:29 PM, Michał Górny wrote:
> > Dnia 2013-08-03, o godz. 17:54:42
> > Ulrich Mueller <ulm@g.o> napisał(a):
> >
> >>>>>>> On Sat, 3 Aug 2013, Michał Górny wrote:
> >>
> >>> 2. The eclass comes with a pure bash-3.2 CamelCase converter for
> >>> changing PNs like 'twisted-foo' into 'TwistedFoo'. The relevant code
> >>> can be moved to eutils as portable replacements for bash-4 ${foo^}
> >>> and friends.
> >>
> >>> 		# obtain octal ASCII code for the first letter.
> >>> 		local ord=$(printf '%o' "'${fl}")
> >>>
> >>> 		# check if it's [a-z]. ASCII codes are locale-safe.
> >>> 		if [[ ${ord} -ge 141 && ${ord} -le 172 ]]; then
> >>> 			# now substract 040 to make it upper-case.
> >>> 			# fun fact: in range 0141..0172, decimal '- 40' is fine.
> >>> 			local ord=$(( ${ord} - 40))
> >>> 			# and convert it back to the character.
> >>> 			fl=$(printf '\'${ord})
> >>> 		fi
> >>
> >> This looks just horrible. You do decimal arithmetic on octal numbers?
> >
> > Yes. Bash wasn't really happy to do octal arithmetic for me. Yet
> > in this particular case, with proper assumptions, decimal arithmetic is
> > practically equivalent.
> >
>
> 		# obtain decimal ASCII code for the first letter.
> 		local fl=$(printf '%d' "'${w}")
>
> 		# check if it's [a-z]. ASCII codes are locale-safe.
> 		if [[ ${ord} -ge 97 && ${ord} -le 122 ]]; then
> 			local ord=$(( ${ord} - 32 ))
> 			# and convert it back to the character.
> 			fl=$(printf '\'${ord})
> 		fi
>
> 		echo -n "${fl}${w:1}"
>
> Probably var names should be adjusted, I'm not too familiar with bash
> locals.
>
> printf '%d' "'twisted" outputs "116" as expected, similar to
> printf("%d", *"asdf qwerty") in C.
>
> Tested in Bash 4.2.45.

You could test the whole snippet, not just the beginning. Then you
would know that you're passing decimal to '\ooo' which expects octal.

-- 
Best regards,
Michał Górny