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On Wednesday, 23 January 2019 2:32:43 PM AEDT Adam Carter wrote: |
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> > $ printf '0.1.2.3 01.2.3.4 1.2.3.0 1.2.000.3\n' | \ |
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> > |
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> > sed 's/0*\([[:digit:]]\+\)/\1/g' |
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> > |
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> > 0.1.2.3 1.2.3.4 1.2.3.0 1.2.0.3 |
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> |
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> Hi David - thanks for that. |
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> |
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> So [[:digit:]] is another way of writing [0-9] and the + just means another |
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> instance of the proceeding expression, right, so your and Francois |
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> solutions are functionally the same, and all the following are the same |
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> too, right? |
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> |
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> [[:digit:]]+ |
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> [[:digit:]][[:digit:]] |
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> [0-9]+ |
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> [0-9][0-9] |
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Not quite. |
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A trailing '+' means "1 or more of the preceding item", while a trailing '*' |
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means "0 or more". |
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[0-9]+ would match any string consisting of only digits, no matter how long, |
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but not an empty string. |
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-- |
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Reverend Paul Colquhoun, ULC. http://andor.dropbear.id.au/ |
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Asking for technical help in newsgroups? Read this first: |
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http://catb.org/~esr/faqs/smart-questions.html#intro |
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