1 files changed, 23 insertions, 0 deletions
diff --git a/usr/nslookup.c b/usr/nslookup.c
new file mode 100644
index 0000000..6a531b8
--- /dev/null
+++ b/usr/nslookup.c
@@ -0,0 +1,23 @@
+#include "resolve.h"
+/* nslookup HOST - resolve a hostname to an IPv4 address via DNS over UDP.
+   All the DNS logic lives in resolve.h (shared with wget). */
+
+static unsigned char namebuf[64];     /* first so it lands past the arg at 0xA000 */
+static unsigned char ip[4];
+
+void main(void) {
+    char *host;
+    unsigned char i;
+    host = getargs();
+    if (!host || !*host) { puts("usage: nslookup HOST"); nl(); sexit(1); }
+    for (i = 0; host[i] && i < 63; i++) namebuf[i] = (unsigned char)host[i];
+    namebuf[i] = 0;
+
+    if (resolve((char *)namebuf, ip)) {
+        puts((char *)namebuf); puts(" -> ");
+        for (i = 0; i < 4; i++) { putu(ip[i]); if (i < 3) putc('.'); }
+        nl();
+    } else {
+        puts("nslookup: cannot resolve "); puts((char *)namebuf); nl();
+    }
+}