Extract lines
Extract lines. Runs entirely on your device, nothing is uploaded.
Extract lines keeps only the lines of a pasted text that match a substring or regex, fall inside a numbered range, or both. invert flips the selection to keep everything that does not match. A pattern and a range can combine, but giving neither is refused outright. Ranges are 1-based and inclusive of both ends.
Questions
Can I combine a pattern and a line range?
Yes. Give both and a line has to satisfy the range first, then the pattern test is applied on top of what the range selected; giving neither is refused with "extract-lines needs a pattern, a range, or both".
How does invert behave with only a range and no pattern?
It flips the range selection itself, keeping every line outside the given range instead of inside it, since there is no pattern test to invert in that case.
What format does the range need to be in?
Exactly "start-end", both whole numbers, 1-based and inclusive, such as "3-10". Anything else is refused with a message quoting what you gave and what format is expected.
Can the pattern be a regular expression?
Yes, if useRegex is turned on; otherwise pattern is matched as a plain substring anywhere in the line. An invalid regex is refused with the JavaScript engine's own error message included.
Are matched line numbers preserved in the output?
No. The output is only the matching lines themselves, in their original order, with no line-number prefix; combine it with Number lines afterward if you need the original positions.
Compare
| Tool | Runs on the CLI | Live as you type |
|---|---|---|
| Extract lines | Yes | Yes |
| Number lines | Yes | Yes |
| Reverse lines | Yes | Yes |
| Shuffle lines | Yes | Yes |
| Sort lines by length | Yes | Yes |
| Unique lines with counts | Yes | Yes |
| Prefix or suffix lines | Yes | Yes |