uutils/findutils

-printf: unrecognized %X / \X directives should warn and print literally, not be dropped or error

Open

#815 opened on Aug 7, 2026

View on GitHubContributor guide
 (0 comments) (0 reactions) (0 assignees)Rust (96 forks)user submission
good first issue

Repository metrics

Stars
 (635 stars)
PR merge metrics
 (Avg merge 26d 6h) (46 merged PRs in 30d)

Description

GNU findutils treats an unrecognized -printf directive as a warning and prints the directive text verbatim, exiting 0. uutils/findutils diverges in two ways.

%X - the % is silently dropped

$ # GNU findutils 4.10.0
$ find d -printf '%€|\n'
find: warning: unrecognized format directive '%€'
%€|
$ echo $?
0

$ # uutils
$ find d -printf '%€|\n'
€|
$ echo $?
0

The % disappears. Same for the ASCII case, e.g. %q.

\X - uutils errors instead of warning

$ # GNU: warns, prints `\€`, exit 0
$ # uutils: hard error, exit 1

Contributor guide

Research direction
Inspect the printf parser in the source code. Identify where percent and backslash directives are interpreted. Compare with GNU findutils behavior for unrecognized directives, then add tests and modify the parser to warn and print literally.
Tech stack
rust
Domain
cli
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
GitRust
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75