PlainSift

Filter lines containing text

Keep matching lines or remove them using a literal substring comparison, with “error” as the initial search term.

Runs in your browser. Your text is not uploaded.

Worked example

Before

ERROR: missing name
ready
minor error found
done

After

ERROR: missing name
minor error found

Default case-insensitive keep mode retains the two lines containing “error”.

Exactly what this changes

  • The default keeps lines containing the search text and ignores letter case. Matching checks each complete line for one literal substring; it does not split words, infer meaning, or evaluate regular-expression syntax.
  • Switch the mode to remove matches when the named fragment identifies unwanted rows. Nonmatching lines keep their exact text and relative order, including duplicates, indentation, punctuation, and Unicode code points.
  • An empty search term is invalid because every string contains an empty substring. PlainSift reports the local error and leaves both source text and the previous output untouched instead of returning a surprising empty or complete list.

Options and edge cases

  • Enable case sensitivity when uppercase and lowercase forms should differ. The search field itself is never trimmed automatically, so spaces entered at either edge are part of the literal value to match.
  • The search term remains only in private workspace memory. It is not encoded in the URL, stored by the browser, sent to the public parent, included in resize messages, or transmitted in a request.

Edge case: Metacharacters such as brackets, dots, stars, and backslashes have no special behavior. Initial-release filtering is literal only and deliberately does not execute regular expressions.