When MIT/GNU Scheme is started, the current working directory (or
simply, working directory) is initialized in an operating-system
dependent manner; usually, it is the directory in which Scheme was
invoked. The working directory can be determined from within Scheme by
pwd procedure, and changed by calling the
procedure. Each REP loop has its own working directory, and
inferior REP loops initialize their working directory from the
value in effect in their superior at the time they are created.
Returns the current working directory as a pathname that has no name, type, or version components, just host, device, and directory components.
pwdis an alias for
working-directory-pathname; the long name is intended for programs and the short name for interactive use.
Makes filename the current working directory and returns the new current working directory as a pathname. Filename is coerced to a pathname using
cdis an alias for
set-working-directory-pathname!; the long name is intended for programs and the short name for interactive use.
set-working-directory-pathname!modifies the value of
*default-pathname-defaults*by merging the new working directory into it.
When this procedure is executed in the top-level REP loop, it changes the working directory of the running Scheme executable.(set-working-directory-pathname! "/usr/morris/blisp") => #[pathname "/usr/morris/blisp/"] (set-working-directory-pathname! "~") => #[pathname "/usr/morris/"]
This procedure signals an error if filename does not refer to an existing directory.
If filename describes a relative rather than absolute pathname, this procedure interprets it as relative to the current working directory, before changing the working directory.(working-directory-pathname) => #[pathname "/usr/morris/"] (set-working-directory-pathname! "foo") => #[pathname "/usr/morris/foo/"]
This procedure temporarily rebinds the current working directory to filename, invokes thunk (a procedure of no arguments), then restores the previous working directory and returns the value yielded by thunk. Filename is coerced to a pathname using
pathname-as-directory. In addition to binding the working directory,
with-working-directory-pathnamealso binds the variable
*default-pathname-defaults*, merging the old value of that variable with the new working directory pathname. Both bindings are performed in exactly the same way as dynamic binding of a variable (see Dynamic Binding).