is_named_pipe
pass = is_named_pipe(TPIPE);
pass = pass && !is_named_pipe("%s", TEXIST);
pass = pass && !is_named_pipe(TEXE);
int is_named_pipe(const char *, ...) __printflike(1, 2);
if (!is_named_pipe("%s", T_NPIPE(c)->in_pipename)) {
while (!is_named_pipe("%s", T_NPIPE(c)->in_pipename)) {