PatternRegex
Find blank lines
Locate empty or whitespace-only lines in a file or document, useful for tidying up extra spacing before a diff or a print.
Last updated
Matches
- Line one Line three
- Para one Para two
Doesn’t match
- Line one Line two Line three
- No blank lines All rows have text Final row here
Why it’s written this way
\s*$ says a line may contain zero or more whitespace characters and nothing else, so it matches both a truly empty line and one that's only spaces or a leftover tab.
The m flag redefines ^ and $ to mean the start and end of each line rather than the start and end of the whole string, which is what lets one pattern check every line of a multi-line document in a single pass.
Edge cases to know
- →\s also matches newline characters, so a run of several blank lines back to back can produce more matches than you'd expect from counting them by eye.
- →It treats a line of pure spaces exactly like a truly empty line — if you need to tell those apart, swap \s*$ for a check that excludes newline explicitly.