Per, AWK and Sed Tricks for Text File Manipulation

Selecting a paragraph with first line known

/^first line content$/,/^$/ works in both AWK and sed for addressing a paragraph, or any content with unique start and end identifiers.

sed -i -e '/^Package: angie-module-wasmtime$/,/^$/d' debian/control

Perl paragraph mode

-00 is a special value that cause Perl to slurp files in paragraph mode. This is very useful if we need to match text in the middle of a paragraph, which is more difficult for a line-oriented editor like sed.

perl -i -00 -ne 'print unless /wasmtime/' debian/rules

In AWK, you could use -v RS= to read inputs in paragraph, but you will also need -v ORS='\n\n' to set the output separator.

Note that both Perl paragraph mode and AWK’s -v RS= rewrites the output separators, so if your file has more than three consecutive newlines, they will be rewritten.