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load-logical-pathname-translations

load-logical-pathname-translations Function

Syntax:

load-logical-pathname-translations host → just-loaded

Arguments and Values:

host—a string.

just-loaded—a generalized boolean.

Description:

Searches for and loads the definition of a logical host named host, if it is not already defined. The specific nature of the search is implementation-defined.

If the host is already defined, no attempt to find or load a definition is attempted, and false is returned. If the host is not already defined, but a definition is successfully found and loaded, true is returned. Otherwise, an error is signaled.

Examples:

(translate-logical-pathname "hacks:weather;barometer.lisp.newest") 
▷ Error: The logical host HACKS is not defined. 
(load-logical-pathname-translations "HACKS") 
▷ ;; Loading SYS:SITE;HACKS.TRANSLATIONS 
▷ ;; Loading done. 
→ true 
(translate-logical-pathname "hacks:weather;barometer.lisp.newest") 
→ #P"HELIUM:[SHARED.HACKS.WEATHER]BAROMETER.LSP;0" 
(load-logical-pathname-translations "HACKS") 
→ false

Exceptional Situations:

If no definition is found, an error of type error is signaled.

See Also:

logical-pathname

Notes:

Logical pathname definitions will be created not just by implementors but also by programmers. As such, it is important that the search strategy be documented. For example, an implementation might define that the definition of a host is to be found in a file called “host.translations” in some specifically named directory.

Expanded Reference: load-logical-pathname-translations​

Loading translations for a logical host​

load-logical-pathname-translations searches for and loads the translation definitions for a logical host. The search mechanism is implementation-defined. It returns true if translations were loaded, nil if the host was already defined.

;; If "SYS" is already a known logical host, returns false
(load-logical-pathname-translations "SYS")
;; => NIL  ; host already defined, implementation-dependent

Returns false for already-defined hosts​

If the host is already defined (e.g., via a prior setf of logical-pathname-translations), no loading is attempted and false is returned.

(setf (logical-pathname-translations "MYKNOWNHOST")
      '(("**;*.*.*" "/tmp/**/*.*")))

(load-logical-pathname-translations "MYKNOWNHOST")
=> NIL

Error on unknown host with no definition file​

If the host is not defined and no definition can be found by the implementation's search mechanism, an error is signaled.

;; This will signal an error if "NONEXISTENT-HOST-XYZ" has no
;; translation file available:
;; (load-logical-pathname-translations "NONEXISTENT-HOST-XYZ")
;; => ERROR: No translations found for logical host NONEXISTENT-HOST-XYZ