How is it different from fgrep-by-string?

fgrep-by-string keeps matching files. ungrep-by-string is the inverse and keeps the non-matching ones.

Does it edit file contents?

No. It filters at the file level, passing whole files through or dropping them, rather than rewriting contents.

Which inputs does the node take?

ungrep-string and folder-with-files. There are no snapshot CLI flags for this utility.

When should I ungrep instead of fgrep?

Use ungrep-by-string when the noise string is rarer than the keepers: drop a few polluted files and let the rest continue. Use fgrep-by-string when you want only the matches.

Updated Jul 15, 2026

Utilities

Prune files that contain a known noise string

Inverse file filter: keep files that lack a given string.

Strip out a known false positive Drop out-of-scope output Clean a folder between pipeline stages

overview

What ungrep-by-string does

ungrep-by-string is a folder-level inverse filter. Pass ungrep-string and folder-with-files; it keeps files that do not contain the string and drops the ones that do.

Reach for it when a known false positive, placeholder, or out-of-scope marker pollutes a results folder and the next stage should never see those files.

Trickest provides ungrep-by-string as a managed Utilities node. Outputs FILE and FOLDER of survivors. Pair with fgrep-by-string when you need the matching set instead.

use cases

Where ungrep-by-string fits

Strip out a known false positive

Remove every file in a results folder that contains a string you have already triaged as noise, so downstream stages never see it again.

Drop out-of-scope output

Filter a folder of tool results to discard files mentioning a host or path that is outside scope, keeping the workflow focused.

Clean a folder between pipeline stages

Insert ungrep-by-string after a collector to prune unwanted files in place, with no manual editing, before the next tool consumes the folder.

Invert a grep filter

When you need the files that do not match rather than the ones that do, ungrep-by-string gives you the complement of a normal content filter.

reference

ungrep-by-string inputs and flags

2 inputs

Name	Type	Flag	Description
ungrep-string	STRING	·	String that files must not contain to pass through.
folder-with-files	FOLDER	·	Folder of files to filter by the ungrep string.

Showing key inputs. ungrep-by-string exposes 2 inputs in total.

example

Run ungrep-by-string

ungrep-by-string · command

# ungrep-by-string: drop files that mention out-of-scope noise# inputs: folder-with-files=results/  ungrep-string=out-of-scope.example.org# kept files still list in-scope hosts only

sample output

api.example.comapp.example.comstaging.example.comdev.example.commail.example.comcdn.example.comvpn.example.comwww.example.com

guidance

Choosing ungrep-by-string

Use ungrep-by-string when a folder of tool output carries a string you want gone and non-matching files should continue. It filters whole files, not lines. For keeping matches use fgrep-by-string; for URL list collapse use urldedupe; for URL part extraction use unfurl.

fgrep-by-string

Keeps files that contain the string. ungrep-by-string keeps the ones that do not.

gron

Flattens JSON for line greps. ungrep-by-string filters whole files in a folder.

anew

Appends only new, unseen lines. ungrep-by-string removes files by content instead.

faq

ungrep-by-string questions

Files in the folder that do not contain ungrep-string. Files that do contain it are dropped.

Run ungrep-by-string yourself

A folder of files feeds ungrep-by-string, which drops every file containing the noise string and writes the surviving files as a queryable output.

Run ungrep-by-string in Trickest Browse the library

Facts on this page come from the live Trickest tool library.