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Mike Frysinger wrote: |
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> On Tuesday 21 July 2009 06:13:25 Steven J Long wrote: |
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>> Nikos Chantziaras wrote: |
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>> > Thanks. I ended up doing it this way, though with only one loop in |
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>> > src_install(), which seems to be a bit more efficient and shorter: |
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>> > |
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>> > |
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>> > LANGUAGES="de" |
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>> > for i in ${LANGUAGES}; do |
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>> > IUSE="${IUSE} linguas_${i}" |
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>> > done |
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>> |
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>> Just on a side-note (not saying it's how you want to do this one), this |
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>> is something that BASH arrays are nice for (saving another loop): |
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>> $ foo=(bar baz quux) |
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>> $ echo "prefixed: '${foo[*]/#/pfx_}'" |
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>> prefixed: 'pfx_bar pfx_baz pfx_quux' |
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> |
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> printf would probably be better as it is typically a shell builtin and it |
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> doesnt require use of arrays/uncommon syntax. |
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> media-gfx/exiv2/exiv2-0.18.ebuild: |
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> IUSE_LINGUAS="de es fi fr pl ru sk" |
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> IUSE="${IUSE} $(printf 'linguas_%s ' ${IUSE_LINGUAS})" |
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Doh, forgot about printf. (We have alias print="printf '%s\n'" in our lib |
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code which comes in handy too.) Nice one. |
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The only issue with the above is that it requires a subshell; forking isn't |
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cheap (especially on Interix/cygwin/doze) and in general it's considered a |
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bit lame (at least amongst the ##bash old-timers that I bump heads with) to |
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need forking in BASH, though ofc not in SH, which is why it might not be |
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the best here, since the metadata generation phase is a restricted subset |
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of SH, leave alone BASH, at least aiui. |
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An example of BASH saving forking, would be where printf -v comes into play. |
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A more portable, though less flexible command in terms of allowed |
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characters is read from <<< [1]. Though that can be worked round, it's nice |
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not to have to; a shell that is progressing while still retaining excellent |
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portability is useful imo (so long as we don't get our knickers in a twist |
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about using new features, since we can set a required EAPI per-profile in |
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any case.) |
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[1] @freenode: /msg greybot <<< |
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Yes, I'm aware there are two versions of portability being discussed there. |
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I figured our readership can differentiate, and if not you can always |
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lead 'em gently by the hand to Massachusetts.. ;P |
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-- |
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#friendly-coders -- We're friendly but we're not /that/ friendly ;-) |
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