Implement scheme begin forms, filedescriptor dup()ing and use print-error-message to print the error message, then exit

1 files changed, 14 insertions, 2 deletions

diff --git a/scsh-process.scm b/scsh-process.scm
index ca747e2..74727ce 100644
--- a/scsh-process.scm
+++ b/scsh-process.scm
@@ -24,7 +24,8 @@
                      (handle-exceptions exn
                        ;; TODO: Figure out how SCSH does this.  It shows the error
                        ;; on stderr in the REPL, but then still quits it.
-                       (begin ((##sys#error-handler) exn) (exit 1))
+                       ;; If we just invoke current-handler, it'll get a second REPL
+                       (begin (print-error-message exn) (exit 1))
                        (exec-epf ?epf ...)))))))
 
 (define-syntax run
@@ -57,6 +58,12 @@
                        `?fd))
     ((_ (<< ?fd ?object)) (error "<< currently not implemented"))
     ((_ (>> ?fd ?object)) (error ">> currently not implemented"))
+    ((_ (= ?fd-from ?fd/port-to))
+     (let* ((fd/port-to ?fd/port-to)    ; Evaluate once
+            (fd-to (if (port? fd/port-to)
+                       (port->fileno fd/port-to)
+                       fd/port-to)))
+       (duplicate-fileno ?fd-from fd-to)))
     ((_ (- ?fd/port))
      (let ((o `?fd/port))
        (cond
@@ -73,7 +80,12 @@
 
 ;; The most "core" syntax form
 (define-syntax exec-epf
-  (syntax-rules ()
+  (syntax-rules (begin)
+    ((_ (begin ?expr0 ...))
+     (begin (setup-redirection (= 0 (current-input-port)))
+            (setup-redirection (= 1 (current-output-port)))
+            (setup-redirection (= 2 (current-error-port)))
+            ?expr0 ...))
     ((_ (?prog ?arg0 ...) ?redir0 ...)
      (begin
        (setup-redirection ?redir0) ...