.fs.* — filesystem

Minimal filesystem-metadata primitives. The namespace is deliberately small: two builtins cover the common needs (file size, directory listing) and the predicate cases (exists / is-file / is-dir) are reached by try-wrapping .fs.size or .fs.list.

Always available

.fs.size and .fs.list are read-only and unrestricted — they remain callable for IPC peers even when the server is started with -U.

Reference

Function	Arity	Flags	Description
.fs.size	unary	—	File size in bytes.
.fs.list	unary	—	Sorted sym vector of directory entries.

.fs.size

Signature: (.fs.size "path"). Returns the file size in bytes as an i64.

Errors: type (arg not a string), io (path missing or names a directory rather than a file). Wrap in try to distinguish "doesn't exist" from "is a directory" without parsing error messages — both surface as io.

(.fs.size "/etc/hosts")
;; => 213

(try (.fs.size "/missing"))
;; => <error: io>

.fs.list

Signature: (.fs.list "path"). Returns a sym vector of entries in the directory, sorted lexicographically. The . and .. entries are filtered out.

Errors: type (arg not a string), io (path is not a directory, or doesn't exist).

(.fs.list "/etc")
;; => ['hosts 'passwd 'resolv.conf ...]

Use this as a building block — find-style recursive walks can be expressed by mapping .fs.list over the result and filtering with .fs.size / try.

See also

• .os.* — process-environment access (getenv / setenv).
• .sys.exec — shell out for anything not covered here (test predicates, deletes, recursive operations).