diag(inventory): probe BAR: device-name/mode candidates (BAR:D etc.)

code/inventory/scan.c

@@ -1,39 +1,52 @@
 /*
  * scan.c - Phase 1 barcode diagnostic for the Workabout MX integral laser.
  *
- * Loads the EAN/UPC decoder LDD (BAREAN.LDD), opens the decoder device (BAR:),
- * and dumps every byte of each read so the decoded format (length, any prefix
- * or type byte, terminator) can be confirmed.
+ * The EAN/UPC decoder LDD (BAREAN.LDD) is loaded, then the decoder device is
+ * opened. The exact device-name form and open mode are not documented in the
+ * available manuals (they live in the I/O Devices Reference), so this build
+ * tries several candidates in one run and reports which one opens - most
+ * likely "BAR:D" (the decoder over port D, like TTY:D), since bare "BAR:"
+ * returns E_FILE_NAME (-38). Once open, it dumps every byte of each read so
+ * the decoded UPC format can be seen.
  *
- * The load and open results are printed and then a key is waited for BEFORE
- * anything else, so the numbers stay on screen even if the open fails (a failed
- * open would otherwise return instantly and the System screen would wipe the
- * message). Blocking I/O throughout; exit via the System screen.
+ * Blocking I/O; exit via the System screen.
  */
 #include <plib.h>
 #include "bcode.h"
 
+#define NCAND 5
+
 GLDEF_C INT main(VOID)
 {
     VOID *chan;
     UBYTE buf[64];
-    INT   loadErr, openErr, n, i;
+    INT   loadErr, r, n, i, opened;
+    UINT  k;
+
+    static TEXT *names[NCAND] = { "BAR:D", "BAR:D", "BAR:",  "BAR:E", "BAR:A" };
+    static UINT  modes[NCAND] = { (UINT)-1, 0,      0,       (UINT)-1, (UINT)-1 };
 
     loadErr = bcodeLoad();
-    openErr = bcodeOpen(&chan);
+    p_printf("load %s.LDD: %d\n\n", BCODE_LDD, loadErr);
 
-    /* Show both results and hold the screen until a key is pressed. */
-    p_printf("load %s.LDD : %d\n", BCODE_LDD, loadErr);
-    p_printf("open %s    : %d\n", BCODE_DEV, openErr);
-    p_printf("\n(0 = ok; for load, an 'already loaded' error is also ok)\n");
-    p_printf("Press a key to continue...\n");
+    opened = 0;
+    for (k = 0; k < NCAND; k++) {
+        r = p_open(&chan, names[k], modes[k]);
+        p_printf("open \"%s\" mode %u: %d\n", names[k], modes[k], r);
+        if (r >= 0) {
+            opened = 1;
+            break;
+        }
+    }
+
+    if (opened == 0) {
+        p_printf("\nNothing opened. Press a key to exit.\n");
         p_getch();
-
-    if (openErr < 0)
         return 1;
+    }
 
-    p_printf("\n%s open. Scan a barcode. Exit via the System screen.\n\n",
-             BCODE_DEV);
+    p_printf("\nOpened \"%s\". Scan a barcode. System screen to exit.\n\n",
+             names[k]);
 
     for (;;) {
         n = p_read(chan, buf, sizeof(buf));