--- unix/tclUnixPipe.c
+++ unix/tclUnixPipe.c  2000/12/19 12:55:59
@@ -189,7 +189,7 @@
     if (tmpnam(fileName) == NULL) {                    /* INTL: Native. */
        return NULL;
     }
-    fd = open(fileName, O_RDWR|O_CREAT|O_TRUNC, 0666); /* INTL: Native. */
+    fd = open(fileName, O_RDWR|O_CREAT|O_EXCL, 0666);  /* INTL: Native. */
     if (fd == -1) {
        return NULL;
     }
