A shell-native cd-compatible directory jumper using power-law frecency
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…
A shell-native cd-compatible directory jumper using power-law frecency launched on March 4, 2026 with 26 votes, #808 of 23,380 launches that month and more than 95% of that year's launches.
In plain words
This shell-native directory jumper helps users navigate frequently-used folders by learning from their cd history. It ranks directories using a power-law frecency model that considers patterns across hundreds of past actions rather than just the most recent visit, preventing occasional bursts of activity from disrupting long-term navigation habits. Query responses complete in 20-30 milliseconds, remaining fast enough for seamless shell integration. The tool has been privately maintained since 2011 and is designed for developers and power users who frequently switch between multiple project directories.
written from the facts on this page · September 2026
From the sources
cd replacement with pattern matching and explicit "frecency" scoring over recorded visit history. - jghub/sd-switchdir
SD is a directory navigation utility for ksh93u+, bash $\ge$ 4.2, and zsh $\ge$ 4.3, using frequency–recency tracking over an explicit visit history. Ksh-compatibility options are enabled: extglob in bash; KSH_ARRAYS , KSH_GLOB , POSIX_BUILTINS , and SH_WORD_SPLIT in zsh. Note: This project is unrelated to the Rust-based sd text replacement tool. This repository is a read-only snapshot mirror containing tagged stable states. Issues are monitored, and pull requests may be considered for manual integration. SD provides the sd command, designed to act as a drop-in replacement for cd for pathname arguments. In addition, it supports pattern-based directory selection from a dynamically ranked…from github.com
In the maker’s words, at launch
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…
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