Files

3.0 KiB

Design notes

The mechanism

f() wraps a command in a loop with one job: don't fail the same way twice.

  1. Look up whether this exact command line has a known fix, keyed by the literal string of the command and its arguments.
  2. If it does, eval the fix first (a precondition — create a file, export a variable, start a dependency, whatever the fix needs to do), then run the command itself.
  3. If the command still fails, prompt for a fix, log command=fix to p, apply it, and retry.
  4. Repeat until the command succeeds or the user gives up (blank input).

The state file p is the entire "memory" of the system. It's line-oriented, grep-able, diffable, and mergeable — ordinary Unix text, not a database.

Why "autopoietic"

Maturana and Varela coined autopoiesis to describe systems that continuously produce the components that make up the system itself — a living cell doesn't consult an external blueprint; the process of metabolizing is the process that rebuilds the cell's own boundary and machinery.

f() is a deliberately tiny analogy: the artifact it produces (p) is fed back into how the function behaves on its next invocation. There's no separation between "the program" and "the program's own history of repairs" — the history is part of the program's behavior from that point on. It's a toy, not a claim that a shell function is alive — but the self-referential loop (behavior → artifact → behavior) is the same shape.

Known limitations

  • Fixes are preconditions, not replacements. f cmd always re-runs cmd verbatim; the learned fix only gets to run before it. If the actual problem is that cmd itself was wrong (a typo, wrong flag), no precondition can save it — you'd loop forever re-typing the same fix. This is intentional: you're teaching the environment to accommodate the command, not rewriting the command.
  • Keying is exact-string. f ls foo and f ls foo (two spaces) are different keys. There's no fuzzy matching or parameterization.
  • No expiry or invalidation. A fix that made sense once (e.g. "install a package that existed at the time") can go stale, and f has no way to know that. p is meant to be reviewed and edited by hand like any other config file.
  • Shared p across unrelated commands is a security surface. Anyone who can write to p can get arbitrary code eval'd the next time a matching command runs. Treat p with the same trust level as a shell rc file — don't pull one from an untrusted source and source it blind.
  • The 41-byte original recurses instead of looping, and re-reads no per-command key — it only remembers the last fix, for whatever command most recently failed. src/f.sh fixes both, at the cost of a few more lines.

Where this is used

The hardened version boots inside AdaptiveOS — a minimal Alpine-based live ISO that drops you into a shell with f() and its p file living on a tmpfs workspace, so the loop can learn and forget freely within a session.