// the find
tomnomnom/anew
A tool for adding new lines to files, skipping duplicates
A single-purpose CLI that appends lines from stdin to a file, skipping any that already exist, printing only the new lines to stdout. Useful for security recon workflows (subdomains, URLs) or any pipeline where you're accumulating a deduplicated list over time.
Does exactly one thing and the implementation is small enough to read in a minute. Dry-run (-d) and quiet (-q) flags cover the two obvious variants without bloating the interface. Zero dependencies beyond the stdlib, so the binary is tiny and there's nothing to break.
No commit activity since early 2024 and it's a two-file project, so don't expect fixes if you hit an edge case. Dedup is exact-string only — no normalization, trimming, or case-insensitive option, which matters if your input has trailing whitespace or inconsistent casing. Reads the whole target file into memory to build the dedup set, so it won't scale to huge files. No tests in the repo, which is thin for something people pipe untrusted data through.