tasks a-s

Task/Secure-temporary-file/BBC-BASIC/secure-temporary-file.bbc

@@ -0,0 +1,27 @@
+      file% = FNopentempfile
+      IF file% = 0 ERROR 100, "Failed to open temp file"
+      PRINT #file%, "Hello world!"
+      PTR#file% = 0
+      INPUT #file%, message$
+      CLOSE #file%
+      PRINT message$
+      END
+
+      DEF FNopentempfile
+      LOCAL pname%, hfile%, chan%
+      OPEN_EXISTING = 3
+      FILE_FLAG_DELETE_ON_CLOSE = &4000000
+      GENERIC_READ = &80000000
+      GENERIC_WRITE = &40000000
+      INVALID_HANDLE_VALUE = -1
+      DIM pname% LOCAL 260
+      FOR chan% = 5 TO 12
+        IF @hfile%(chan%) = 0 EXIT FOR
+      NEXT
+      IF chan% > 12 THEN = 0
+      SYS "GetTempFileName", @tmp$, "BBC", 0, pname%
+      SYS "CreateFile", $$pname%, GENERIC_READ OR GENERIC_WRITE, 0, 0, \
+      \                 OPEN_EXISTING, FILE_FLAG_DELETE_ON_CLOSE, 0 TO hfile%
+      IF hfile% = INVALID_HANDLE_VALUE THEN = 0
+      @hfile%(chan%) = hfile%
+      = chan%