How can I delete everything until a pattern and everything after another pattern from a line?

I'd use sed

sed 's/^.*\(consectetuer.*elit\).*$/\1/' file

Decoded the sed s/find/replace/ syntax:

• s/^.* -- substitute starting at the beginning of the line (^) followed by anything (.*) up to...
• \( - start a named block
• consectetuer.*elit\. - match the first word, everything (.*) up to the last word (in this case, including the trailing (escaped)dot) you want to match
• \) - end the named block
• match everything else (.*) to the end of the line ($)
• / - end the substitute find section
• \1 - replace with the name block between the \( and the \) above
• / - end the replace

If every line contains both start and end pattern then the easiest way to do this is with grep. Instead of deleting the beginning and ending of each line you can simply output the contents between both patterns. The -o option in GNU grep outputs only the matches:

grep -o 'consectetuer.*elit' file

Note: as mentioned, this only works if every line in the file can be parsed this way. Then again, that's 80% of all typical use-cases.