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The sed FAQ
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4.22. How do I locate a paragraph of text if the paragraph contains a certain regular expression?

Assume that paragraphs are separated by blank lines. For regexes that are single terms, use one of the following scripts:

     sed -e '/./{H;$!d;}' -e 'x;/regex/!d'      # most seds
     sed '/./{H;$!d;};x;/regex/!d'              # GNU sed

To print paragraphs only if they contain 3 specific regular expressions (RE1, RE2, and RE3), in any order in the paragraph:

     sed -e '/./{H;$!d;}' -e 'x;/RE1/!d;/RE2/!d;/RE3/!d'

With this solution and the preceding one, if the paragraphs are excessively long (more than 4k in length), you may overflow sed's internal buffers. If using HHsed, you must add a "G;" command immediately after the "x;" in the scripts above to defeat a bug in HHsed (see section 7.9(5), below, for a description).

The sed FAQ
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   Reprinted courtesy of Eric Pement. Also available at Design by Interspire