Exceptions: Add an exception for ^c

src/fsh.nim

@@ -35,6 +35,7 @@ type
     variable: string
   ShellCommandError = object of ShellError
     command: string
+  InterruptCtrlC = object of CatchableError
 
 # procs for making procedures
 proc newShellException(msg: string, line=0, col=0, whileExec=""): ref ShellError =
@@ -323,4 +324,10 @@ proc eval(cmd: string): string =
 when isMainModule:
   let stdinstrm = stdin.newFileStream
   while not stdinstrm.atEnd():
-    stdinstrm.readCommand.execute.echo
+    try:
+      discard stdinstrm.readCommand.execute
+    except ShellError, ShellCommandError, ShellVariableError:
+      let e = getCurrentException()
+      stderr.write(e.msg, "\n")
+    except InterruptCtrlC:
+      continue