st should compile on NetBSD.

config.mk

@@ -19,6 +19,7 @@ SYSTEM = -D`uname | tr a-z A-Z`
 #SYSTEM = -DLINUX
 #SYSTEM = -DOPENBSD
 #SYSTEM = -DFREEBSD
+#SYSTEM = -DNETBSD
 
 # flags
 CPPFLAGS = -DVERSION=\"${VERSION}\" ${SYSTEM}

st.c

@@ -22,7 +22,7 @@
 
 #if   defined(LINUX)
  #include <pty.h>
-#elif defined(OPENBSD)
+#elif defined(OPENBSD) || defined(NETBSD)
  #include <util.h>
 #elif defined(FREEBSD)
  #include <libutil.h>