What it does
sd is a focused find-and-replace utility for the terminal. It accepts a search pattern and replacement as separate arguments, uses regular expressions by default, and offers a fixed-string mode for text that should not be interpreted as a pattern. It can read from standard input or modify named files, making it useful for a small transformation in a script or a targeted edit across project files.
Try a literal replacement on a stream
A harmless first example is to pass a short string through standard input:
printf 'debug mode\n' | sd -F debug release
The -F option treats debug as literal text, so brackets, dots and other regular-expression characters do not need escaping. Without that flag, the search expression is a regex, and capture groups can be referenced in the replacement. This split-argument syntax is handy when changing a value in a generated text file or renaming a token in a small project configuration.
For a named file, sd before after file.txt edits the file in place. Try the operation on a copy or a version-controlled worktree before applying it broadly; a mistaken pattern can change many matches. The project is intentionally narrower than a general stream editor such as sed: it concentrates on find and replace rather than providing a broad set of text-processing commands.
The repository documents Cargo installation and packages from multiple maintainers. It does not require a hosted service or account for the local CLI, and its source is MIT licensed. No benchmark claims are needed to choose it: the main reason to use sd is its direct search-and-replacement interface.
Strengths
- Keeps the search expression and replacement in separate arguments, avoiding delimiter-heavy substitution syntax.
- Offers a fixed-string option as well as regex captures and stdin input.
Watch out for
- Named files are modified in place, so broad replacements should be previewed on a copy or reviewed in version control.
- Its deliberately narrow purpose does not replace a general-purpose stream editor for other text-processing tasks.
Best for
- Making a focused text replacement in project files or generated output
- Using familiar regular expressions or literal strings in a shell pipeline
Sources
- chmln/sd official repository and README (Oct 26, 2026)
- sd quick guide and installation notes (Oct 26, 2026)
- sd source license (Oct 26, 2026)