Initial data commit

Task/File-input-output/BCPL/file-input-output.bcpl

@@ -0,0 +1,34 @@
+GET "libhdr"
+
+LET start() BE $(
+
+    // Attempt to open the named files.
+    LET source = findinput("input.txt")
+    LET destination = findoutput("output.txt")
+
+    TEST source = 0 THEN
+        writes("Unable to open input.txt*N")
+    ELSE TEST destination = 0 THEN
+        writes("Unable to open output.txt*N")
+    ELSE $(
+
+        // The current character, initially unknown.
+        LET ch = ?
+
+        // Make the open files the current input and output streams.
+        selectinput(source)
+        selectoutput(destination)
+
+        // Copy the input to the output character by character until
+        // endstreamch is returned to indicate input is exhausted.
+        ch := rdch()
+        UNTIL ch = endstreamch DO $(
+            wrch(ch)
+            ch := rdch()
+        $)
+
+        // Close the currently selected streams.
+        endread()
+        endwrite()
+    $)
+$)