Using Regular Expressions in Vim

On OpenBSD and Debian, Vim’s built-in regex support allows simple but powerful text manipulation for notes, drafts, and prose.

Search

• /pattern — forward search for pattern
• ?pattern — backward search
• n / N — repeat search forward/backward
• * / # — search for word under cursor

Replace

• :%s/old/new/g — replace all occurrences in the file
• :%s/old/new/gc — replace with confirmation
• :s/old/new/ — replace on current line only

Anchors and Characters

• ^ — start of line
• $ — end of line
• . — any character
• \s / \S — whitespace / non-whitespace
• \w / \W — word character / non-word
• \+ — one or more
• \* — zero or more
• \{m,n\} — repeat m to n times

Examples for Daily Prose

• Delete trailing spaces:

:%s/\s\+$//e

• Fix double spaces after periods:

:%s/\.  \./. ./g

• Capitalize first word of a paragraph:

:g/^\s*\w/\norm! gUiw

• Highlight TODO comments:

:/TODO

Notes on OpenBSD / Debian

• Base vi may lack some regex features; install full Vim via pkg_add vim (OpenBSD) or apt install vim (Debian).
• :w !sudo tee % works on OpenBSD and Debian for editing protected files.
• Regex operations are safe for plain text and prose, ideal for cleaning drafts, notes, and markdown files.