A shell-native cd-compatible directory jumper using power-law frecency
Details
- External ID
- 47245485
- Source
- HN
- Company
- —
- Product
- A shell-native cd-compatible directory jumper using power-law frecency
- Website domain
- github.com
- Launched
- March 4, 2026
- Cohort
- —
- Upvotes
- 26
- Upvotes percentile
- 0.7755227552275523
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
I have used this tool privately since 2011 to manage directory jumping. While it is conceptually similar to tools like z or zoxide, the underlying ranking model is different. It uses a power-law convolution with the time series of cd actions to calculate a history-aware "frecency" metric instead of the standard heuristic counters and multipliers.This approach moves away from point-estimates for recency. Most tools look only at the timestamp of the last visit, which can allow a "one-off" burst of activity to clobber long-term habits. By convolving a configurable history window (typically the last 1,000+ events), the score balances consistent habits against recent flukes.On performance: Despite the O(N) complexity of calculating decay for 1,000+ events, query time is ~20-30ms (Real Time) in ksh/bash, which is well below the threshold of perceived lag.I intentionally chose a Logical Path (pwd -L) model. Preserving symlink names ensures that the "Name" remains the primary searchable key. Resolving to physical paths often strips away the very keyword the user intends to use for searching.
Enrichment
- Theme
- system maintenance and file utilities
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- directory jumper for shell using frecency
- Manually corrected
- False
Could you build this?
Partial While basic directory jumping shell scripts are simple, implementing a custom power-law convolution frecency algorithm in a low-latency native binary requires rigorous mathematical and systems programming.
What it would actually take: The tool requires an ultra-low-latency native binary (written in C, Rust, or Go) executed on every shell prompt hook without perceptible delay (<5ms). It requires implementing a discretized power-law kernel convolution over timestamped directory transitions, managing atomic binary file persistence to prevent concurrent terminal race conditions, and shell integration across zsh/bash/fish. Mathematical modeling of decay processes and systems-level POSIX shell profiling are required.
Discussion
16 comments analyzed.
Competitors mentioned: zoxide, z, CDPATH with manual aliases, pushd/popd, CTRL-R shell history search
Concerns raised: Requires learning new commands vs. standard cd behavior, 9-30ms latency overhead per cd action, Complexity not justified for users with small, stable project sets, Power-law ranking may not matter in practice vs. simpler heuristics
Feature requests: O(1) frecency computation instead of O(N) window recomputation, Interactive directory selection with fzf integration, Configurable power-law exponent and attention span tuning
Competitors
Other products that read as similar to this one — 33 launches clear the similarity bar, closest 8 shown.
Attention rank: #8 of 34 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 117 days after the earliest competitor.
- Ze.sh · hn · 2026-06-22 · 5 upvotes · similarity 0.68
- hop · github · 2026-09-11 · 7 upvotes · similarity 0.41
- Kosh · hn · 2026-08-28 · 7 upvotes · similarity 0.40
- jev-shell-history · github · 2026-09-18 · 100 upvotes · similarity 0.39
- Smarter Shell History for Zsh · hn · 2026-08-12 · 16 upvotes · similarity 0.38
- Hc: an agentless, multi-tenant shell history sink · hn · 2026-01-16 · 43 upvotes · similarity 0.37
- Forkrun · hn · 2026-03-27 · 151 upvotes · similarity 0.37
- I missed the moving blocks, so I built a real Linux disk defragmenter · hn · 2026-08-25 · 97 upvotes · similarity 0.35
Other launches for this product
- No other launches for this product.
Same idea, different domain
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