scsh-0.6/scsh/top.scm

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;;; The scsh argv switch parser.
;;; Copyright (c) 1995 by Olin Shivers. See file COPYING.
;;; Imports:
;;; COMMAND-PROCESSOR: set-batch-mode?! command-loop
;;; ENSURES-LOADED: really-ensure-loaded
;;; ENVIRONMENTS: set-interaction-environment! environment-ref
;;; environment-define!
;;; ERROR-PACKAGE: error
;;; EVALUATION: eval
;;; EXTENDED-PORTS: make-string-input-port
;;; INTERFACES: make-simple-interface
;;; INTERRUPTS: interrupt-before-heap-overflow!
;;; PACKAGE-COMMANDS-INTERNAL: user-environment config-package
;;; get-reflective-tower
;;; PACKAGE-MUTATION: package-open!
;;; PACKAGES: structure-package structure? make-structure
;;; make-simple-package
;;; RECEIVING: mv return stuff
;;; SCSH-LEVEL-0-INTERNALS: set-command-line-args!
;;; SCSH-VERSION: scsh-version-string
;;;
;;; More imports for the new library-search facility:
;;; HANDLE: with-handler
;;; LIST-LIB: any
;;; SCSH-LEVEL-0: directory-files open-input-file file-directory? getenv
;;; SCSH-LEVEL-0: getenv
;;; SCSH-LEVEL-0: the file-name procs
;;; This should be defined by the package code, but it isn't.
(define (get-struct config-pack struct-name)
(let ((s (environment-ref config-pack struct-name)))
(cond ((structure? s) s)
(else (error "not a structure" s struct-name)))))
;;; ensure-loaded and load-into now write to noise-port anyway
(define (load-quietly filename p)
(if (not (string? filename))
(error "not a string in load-quietly" filename))
(let-fluid $current-noise-port (make-null-output-port)
(lambda () (load-into filename p))))
(define (really-ensure-loaded noise . structs)
(let-fluid $current-noise-port (make-null-output-port)
(lambda ()
(apply ensure-loaded structs))))
;;; The switches:
;;; -o <struct> Open the structure in current package.
;;; -n <package> Create new package, make it current package.
;;; -m <struct> <struct>'s package becomes current package.
;;;
;;; -l <file> Load <file> into current package.
;;; -lm <file> Load <file> into config package.
;;; -ll <file> As in -lm, but search the library path list.
;;;
;;; +lp <dir> Add <dir> onto start of library path list.
;;; lp+ <dir> Add <dir> onto end of library path list.
;;; +lpe <dir> As in +lp, but expand env vars & ~user.
;;; lpe+ <dir> As in lp+, but expand env vars & ~user.
;;; +lpsd Add the script-file's directory to front of path list
;;; lpsd+ Add the script-file's directory to end of path list
;;; -lp-clear Clear library path list to ().
;;; -lp-default Reset library path list to system default.
;;;
;;; These two require a terminating -s or -sfd arg:
;;; -ds Load terminating script into current package.
;;; -dm Load terminating script into config package.
;;;
;;; -e <entry> Call (<entry>) to start program.
;;;
;;; Terminating switches:
;;; -c <exp> Eval <exp>, then exit.
;;; -s <script> Specify <script> to be loaded by a -ds or -dm.
;;; -sfd <num> Script is on file descriptor <num>.
;;; -- Interactive scsh.
;;; Return switch list, terminating switch, with arg, top-entry,
;;; and command-line args.
;;; - We first expand out any initial \ <filename> meta-arg.
;;; - A switch-list elt is either "-ds", "-dm", or a (switch . arg) pair
;;; for a -o, -n, -m, -l, or -lm switch.
;;; - Terminating switch is one of {s, c, #f} for -s or -sfd, -c,
;;; and -- respectively.
;;; - Terminating arg is the <exp> arg to -c, the <script> arg to -s,
;;; the input port for -sfd, otw #f.
;;; - top-entry is the <entry> arg to a -e; #f if none.
;;; - command-line args are what's left over after picking off the scsh
;;; switches.
(define (parse-scsh-args args)
(let lp ((args (meta-arg-process-arglist args))
(switches '()) ; A list of handler thunks
(top-entry #f) ; -t <entry>
(need-script? #f)) ; Found a -ds or -dm?
; (display args (current-output-port))
(if (pair? args)
(let ((arg (car args))
(args (cdr args)))
(cond ((string=? arg "-c")
(if (or need-script? top-entry (not (pair? args)))
(bad-arg)
(values (reverse switches) 'c (car args)
top-entry (cdr args))))
((string=? arg "-s")
(if (not (pair? args))
(bad-arg "-s switch requires argument")
(values (reverse switches) 's (car args)
top-entry (cdr args))))
;; -sfd <num>
((string=? arg "-sfd")
(if (not (pair? args))
(bad-arg "-sfd switch requires argument")
(let* ((fd (string->number (car args)))
(p (fdes->inport fd)))
(release-port-handle p) ; Unreveal the port.
(values (reverse switches) 's p
top-entry (cdr args)))))
((string=? arg "--")
(if need-script?
(bad-arg "-ds or -dm switch requires -s <script>")
(values (reverse switches) #f #f top-entry args)))
((or (string=? arg "-ds")
(string=? arg "-dm")
(string=? arg "+lpsd")
(string=? arg "lpsd+")
(string=? arg "-lp-default")
(string=? arg "-lp-clear"))
(lp args (cons arg switches) top-entry #t))
((or (string=? arg "-l")
(string=? arg "-lm")
(string=? arg "-ll")
(string=? arg "lp+")
(string=? arg "+lp")
(string=? arg "lpe+")
(string=? arg "+lpe"))
(if (pair? args)
(lp (cdr args)
(cons (cons arg (car args)) switches)
top-entry
need-script?)
(bad-arg "Switch requires argument" arg)))
((or (string=? arg "-o")
(string=? arg "-n")
(string=? arg "-m"))
(if (pair? args)
(let* ((s (car args))
(name (if (and (string=? arg "-n")
(string=? s "#f"))
#f ; -n #f treated specially.
(string->symbol s))))
(lp (cdr args)
(cons (cons arg name) switches)
top-entry
need-script?))
(bad-arg "Switch requires argument" arg)))
((string=? arg "-e")
(lp (cdr args) switches
(string->symbol (car args)) need-script?))
(else (bad-arg "Unknown switch" arg))))
(values (reverse switches) #f #f top-entry '()))))
(define default-lib-dirs '("/usr/local/lib/scsh/modules/"))
;;; Do each -ds, -dm, -o, -n, -m, -l/lm/ll, +lp/+lpe/lp+/lpe+, or
;;; -lp-clear/lp-default switch, and return the final result package and a
;;; flag saying if the script was loaded by a -ds or -dm.
(define (do-switches switches script-file)
;; We don't want to try to parse $SCSH_LIB_DIRS until we actually
;; need the value -- if the user is using the -lp-default switch,
;; for example, a parse error shouldn't effect the startup.
(define %mod-dirs #f)
(define (mod-dirs)
(if (not %mod-dirs) (set! %mod-dirs (parse-lib-dirs-env-var)))
%mod-dirs)
(define (set-mod-dirs! val) (set! %mod-dirs val))
; (format #t "Switches = ~a~%" switches)
(let lp ((switches switches)
(script-loaded? #f))
(if (pair? switches)
(let ((switch (car switches))
(switches (cdr switches)))
; (format #t "Doing switch ~a~%" switch)
(cond
((equal? switch "-ds")
(load-quietly script-file (interaction-environment))
; (format #t "loaded script ~s~%" script-file)
(lp switches #t))
((equal? switch "-dm")
(load-quietly script-file (config-package))
; (format #t "loaded module ~s~%" script-file)
(lp switches #t))
((equal? switch "-lp-clear")
(set-mod-dirs! '())
(lp switches script-loaded?))
((equal? switch "-lp-default")
(set-mod-dirs! default-lib-dirs)
(lp switches script-loaded?))
((equal? switch "+lpsd")
(set-mod-dirs! (cons 'script-dir (mod-dirs)))
(lp switches script-loaded?))
((equal? switch "lpsd+")
(set-mod-dirs! (append (mod-dirs) '(script-dir)))
(lp switches script-loaded?))
((string=? (car switch) "-l")
; (format #t "loading file ~s~%" (cdr switch))
(load-quietly (cdr switch) (interaction-environment))
(lp switches script-loaded?))
((string=? (car switch) "-lm")
; (format #t "loading module file ~s~%" (cdr switch))
(load-quietly (cdr switch) (config-package))
(lp switches script-loaded?))
((string=? (car switch) "-ll")
(load-library-file (cdr switch) (mod-dirs) script-file)
(lp switches script-loaded?))
((string=? (car switch) "+lp")
(set-mod-dirs! (cons (cdr switch) (mod-dirs)))
(lp switches script-loaded?))
((string=? (car switch) "lp+")
(set-mod-dirs! (append (mod-dirs) (list (cdr switch))))
(lp switches script-loaded?))
((string=? (car switch) "+lpe")
(set-mod-dirs! (cons (expand-lib-dir (cdr switch)) (mod-dirs)))
(lp switches script-loaded?))
((string=? (car switch) "lpe+")
(set-mod-dirs! (append (mod-dirs)
(list (expand-lib-dir (cdr switch)))))
(lp switches script-loaded?))
((string=? (car switch) "-o")
(let ((struct-name (cdr switch))
(cp (config-package)))
;; Should not be necessary to do this ensure-loaded, but it is.
(really-ensure-loaded #f (get-struct cp struct-name))
(package-open! (interaction-environment)
(lambda () (get-struct cp struct-name)))
; (format #t "Opened ~s~%" struct-name)
(lp switches script-loaded?)))
((string=? (car switch) "-n")
(let* ((name (cdr switch))
(pack (new-empty-package name))) ; Contains nothing
(if name ; & exports nothing.
(let* ((iface (make-simple-interface #f '()))
(struct (make-structure pack iface)))
(environment-define! (config-package) name struct)))
(set-interaction-environment! pack)
(lp switches script-loaded?)))
((string=? (car switch) "-m")
; (format #t "struct-name ~s~%" (cdr switch))
(let ((struct (get-struct (config-package) (cdr switch))))
; (format #t "struct-name ~s, struct ~s~%" (cdr switch) struct)
(let ((pack (structure-package struct)))
; (format #t "package ~s~%" pack)
(set-interaction-environment! pack)
(really-ensure-loaded #f struct)
; (format #t "Switched to ~s~%" pack)
(lp switches script-loaded?))))
(else (error "Impossible error in do-switches. Report to developers."))))
script-loaded?)))
;;; (user-environment) probably isn't right. What is this g-r-t stuff?
;;; Check w/jar.
(define (new-empty-package name)
(make-simple-package '() #t
(get-reflective-tower (user-environment)) ; ???
name))
(define (with-scsh-initialized interactive? context args thunk)
(with-scsh-sighandlers
interactive?
(lambda ()
(with-autoreaping
(lambda ()
(install-env)
(initialize-cwd)
(init-scsh-vars interactive?)
(start-new-session context
(current-input-port)
(current-output-port)
(current-error-port)
args
(not interactive?))
(with-interaction-environment
(user-environment)
thunk))))))
(define (parse-switches-and-execute all-args context)
(receive (switches term-switch term-val top-entry args)
(parse-scsh-args (cdr all-args))
(begin
(with-scsh-initialized
(not term-switch) context args
(lambda ()
;; Have to do these before calling DO-SWITCHES, because actions
;; performed while processing the switches may use these guys.
(set-command-line-args!
(cons (if (eq? term-switch 's)
(if (string? term-val)
term-val ; Script file.
"file-descriptor-script") ; -sfd <num>
(car all-args))
args))
(let* ((script-loaded? (do-switches switches term-val)))
(if (and (not script-loaded?) ; There wasn't a -ds or -dm,
(eq? term-switch 's)) ; but there is a script,
(load-quietly term-val ; so load it now.
(interaction-environment)))
(cond ((not term-switch) ; -- interactive
(exit
(restart-command-processor
args
context
(lambda ()
(display (string-append
"Welcome to scsh "
scsh-version-string
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" (Gambit-C 4.0)")
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(current-output-port))
(newline (current-output-port))
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(display "Type ,? for help."
(current-output-port))
(newline (current-output-port))
(in-package (user-environment) '())))))
((eq? term-switch 'c)
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(let ((result (eval (read-exactly-one-sexp-from-string term-val)
(interaction-environment))))
(call-exit-hooks)
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(scheme-exit-now 0)))
(top-entry ; There was a -e <entry>.
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(let ((result ((eval top-entry (interaction-environment))
(command-line))))
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(call-exit-hooks)
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(scheme-exit-now 0)))
;; Otherwise, the script executed as it loaded,
;; so we're done.
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(else (call-exit-hooks)
(scheme-exit-now 0)))))))))
(define (read-exactly-one-sexp-from-string s)
(with-current-input-port (make-string-input-port s)
(let ((val (read)))
(if (eof-object? (read)) val
(error "More than one value read from string" s)))))
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;;; placeholder for an extensible mechanism in the future
(define (call-exit-hooks)
(flush-all-ports)
(relinquish-timeslice)
(relinquish-timeslice))
(define (load-library-file file lib-dirs script-file)
; (format (error-output-port) "Load-library-file: ~a ~s\n" file lib-dirs)
(cond ((file-name-absolute? file)
(load-quietly file (config-package)))
;; Search library dirs for FILE.
((find-library-file file lib-dirs script-file) =>
(lambda (iport)
(load-quietly iport (config-package)))) ; Load it.
(else (error "Couldn't find library module file" file lib-dirs))))
;;; Search library dirs for FILE.
(define (find-library-file file lib-dirs script-file)
(letrec ((recur (lambda (dir)
; (format (error-output-port) "flf -- entering ~a\n" dir)
(let* ((f (string-append dir file))) ; Resolve it.
(or (check-file-for-open f) ; Found it.
(any (lambda (f) ; Search subdirs.
(let ((dir (string-append dir f "/")))
(and (file-directory?/safe dir) (recur dir))))
(directory-files/safe dir)))))))
(any (lambda (dir)
(cond ((eq? dir 'script-dir)
(let* ((script-dir (file-name-directory script-file))
(fname (string-append script-dir file)))
(check-file-for-open fname)))
;; Ends in / means recursive search.
((file-name-directory? dir)
(recur dir))
(else (check-file-for-open (absolute-file-name file dir)))))
lib-dirs)))
;;; (in-any-event abort-exp body ...)
;;; If *anything* goes wrong, bag the BODY forms, and eval ABORT-EXP instead.
(define-syntax in-any-event
(syntax-rules ()
((in-any-event abort-exp body ...)
(call-with-current-continuation
(lambda (ret)
(with-handler (lambda (condition more) (ret abort-exp))
(lambda () body ...)))))))
(define (check-file-for-open f)
(in-any-event #f (let ((iport (open-input-file f)))
(close-input-port iport)
f))) ; Any error, say false.
(define (directory-files/safe dir)
(in-any-event '() (directory-files dir))) ; Any error, say ().
(define (file-directory?/safe f)
(in-any-event #f (file-directory? f))) ; Any error, say false.
;;; Expand out env vars & ~user home dir prefixes.
(define (expand-lib-dir dir)
(substitute-env-vars (resolve-file-name dir)))
;;; Parse up the $SCSH_LIB_DIRS path list.
(define (parse-lib-dirs-env-var)
(let ((s (getenv "SCSH_LIB_DIRS")))
(if (not s) default-lib-dirs
(with-current-input-port (make-string-input-port s)
(let recur ()
(let ((val (read)))
(cond ((eof-object? val) '())
((string? val) (cons val (recur)))
((not val) (append default-lib-dirs (recur)))
(else (error "Illegal path element in $SCSH_LIB_DIRS"
s val)))))))))
(define (bad-arg . msg)
(with-current-output-port (current-error-port)
(for-each (lambda (x) (display x) (write-char #\space)) msg)
(newline)
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(display "Usage: scsh [meta-arg] [switch ..] [end-option arg ...]
meta-arg: \\ <script-file-name>
switch: -e <entry-point> Specify top-level entry point.
-o <structure> Open structure in current package.
-m <package> Switch to package.
-n <new-package> Switch to new package.
-lm <module-file-name> Load module into config package.
-l <file-name> Load file into current package.
-ll <module-file-name> As in -lm, but search the library path list.
+lp <dir> Add <dir> to front of library path list.
lp+ <dir> Add <dir> to end of library path list.
+lpe <dir> +lp, with env var and ~user expansion.
lpe+ <dir> lp+, with env var and ~user expansion.
+lpsd Add script-file's dir to front of path list.
lpsd+ Add script-file's dir to end of path list.
-lp-clear Clear library path list to ().
-lp-default Reset library path list to system default.
-ds Do script.
-dm Do script module.
end-option: -s <script> Specify script.
-sfd <num> Script is on file descriptor <num>.
-c <exp> Evaluate expression.
-- Interactive session.
" (current-error-port)))
(exit -1))
(define (repl)
(command-loop (lambda () (set-batch-mode?! #f))
#f))