Subf

Substitute all occurrences of strings with their replacements. Substitution pairs are read from a TSV file.

Usage

subf <replacements.tsv> <input.txt>

The result is printed to stdout.

Replacements File Format

The replacements file is a TSV (tab-separated values) file where each line contains a match and its replacement, separated by a tab:

value	replacement
broken	correct

• Lines starting with # are treated as comments.
• Matches are case-insensitive and respect word boundaries, so val won't match inside valuable.
• Replacements starting with \u are interpreted as Unicode code points (e.g. \u0041 becomes A).

Example

Given replacements.tsv:

val	replacement
broken	correct

And example.txt:

val
  val
another val
valuable

Broken
  BROKEN
it is broken

Running subf replacements.tsv example.txt outputs:

replacement
  replacement
another replacement
valuable

correct
  correct
it is correct

Installation

npm install subf

Library Usage

Subf can also be used as a library:

import { searchAndReplace } from "subf"

const result = await searchAndReplace("replacements.tsv", "input.txt")

Development

A Nix flake is provided for reproducible setup:

nix develop

Check out the makefile for available commands.