sd

sd is a focused find-and-replace CLI for regex or literal text substitutions in stdin streams and files. It is a local text-transformation primitive for refactors, content cleanup, and scripted rewrites.

• Rewrite matching text in stdin pipelines or files with regex captures or fixed-string replacements.
• Preview replacements before writing, or apply them in place across many files when paired with tools like fd or xargs.
• Handle line-oriented streaming by default, or switch to whole-input mode for multiline patterns and newline replacements.

• stdin and file inputs, stable flags, and in-place editing make it easy to drop into shell loops for local refactors.
• Text output and exit behavior are predictable, but there is no JSON mode and --preview is explicitly a human-readable format that may change.
• Best for local code, config, or content rewrites inside larger workflows rather than service or API operations.

• Files are modified in place by default unless you use --preview, so automated runs should stage changes or rely on version control.
• Multiline work needs --across, which reads whole inputs, uses more memory, and disables streaming.