Tell awk to read from /dev/null.

tests/multiv04.at

@@ -39,7 +39,7 @@ AT_KEYWORDS([multiv04])
 AT_TAR_CHECK([
 
 mkdir directory
-awk 'BEGIN { for (i = 0; i < 1024; i++) printf("genfile -f directory/%014X\n", i); }' | sh
+awk 'BEGIN { for (i = 0; i < 1024; i++) printf("genfile -f directory/%014X\n", i); }' </dev/null | sh
 
 sleep 2