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Jan Kundrát wrote: |
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|
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> Steve Long wrote: |
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>>> Is [[:alpha:]] locale-safe? |
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>>> |
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>> Yes, all POSIX character classes listed here are: |
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>> http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap07.html |
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> |
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> Thanks for a nice link. If I read section 7.3.1 correctly, [[:alpha:]] |
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> always contains those letters, but might contain more, depending on the |
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> locale. So it's probably very minor point, but as long as the script |
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> runs with user-provided locale, one should be explicit here. Or am I |
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> missing something here? |
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> |
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No, that's about the size of it-- if you you'd like to tie it to ASCII, |
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irrespective of locale, that's fair enough. It depends on what you're up to |
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(sorry, I don't have time to go digging through code to see what this |
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applies to) but in the /general/ case it's better to use locale-neutral |
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character-classes, since it makes scripts much more useful. |
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|
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Setting LC_ALL=C temporarily is not a good idea, since it overrides |
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LC_CTYPE. The most common usage for that is for sort order; where that's |
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needed it's better to use LC_COLLATE. (man 7 locale) |
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|
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Quick example showing why the double-bracket appears: |
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if [[ ${v:0:1} != [[:alpha:]_] || $v = *[^[:alnum:]_]* ]]; then |
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errMsg $"$v is not a valid identifier" |
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return 1 |
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fi |
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Getting to know these is really helpful, imo, especially since they apply to |
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_all_ the utilities like tr, sed, grep, awk -- and ed ofc ;) |
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$"text" is for i18n in bash via gettext, akin to _"foo" in C. Can't say I've |
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used it yet, though :p |
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-- |
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