Will this work?

I have an arduino yun. Will this code run normally without the shield?

/*
 
 This example connects to an unencrypted Wifi network. 
 Then it prints the  MAC address of the Wifi shield,
 the IP address obtained, and other network details.

 Circuit:
 * WiFi shield attached
 
 created 13 July 2010
 by dlf (Metodo2 srl)
 modified 31 May 2012
 by Tom Igoe
 */
 #include <WiFi.h>

char ssid[] = "yourNetwork";     //  your network SSID (name) 
char pass[] = "secretPassword";  // your network password
int status = WL_IDLE_STATUS;     // the Wifi radio's status

void setup() {
  //Initialize serial and wait for port to open:
  Serial.begin(9600); 
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
  
  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present"); 
    // don't continue:
    while(true);
  } 
  
 // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED) { 
    Serial.print("Attempting to connect to WPA SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network:    
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:
    delay(10000);
  }
   
  // you're connected now, so print out the data:
  Serial.print("You're connected to the network");
  printCurrentNet();
  printWifiData();

}

void loop() {
  // check the network connection once every 10 seconds:
  delay(10000);
  printCurrentNet();
}

void printWifiData() {
  // print your WiFi shield's IP address:
  IPAddress ip = WiFi.localIP();
    Serial.print("IP Address: ");
  Serial.println(ip);
  Serial.println(ip);
  
  // print your MAC address:
  byte mac[6];  
  WiFi.macAddress(mac);
  Serial.print("MAC address: ");
  Serial.print(mac[5],HEX);
  Serial.print(":");
  Serial.print(mac[4],HEX);
  Serial.print(":");
  Serial.print(mac[3],HEX);
  Serial.print(":");
  Serial.print(mac[2],HEX);
  Serial.print(":");
  Serial.print(mac[1],HEX);
  Serial.print(":");
  Serial.println(mac[0],HEX);
 
}

void printCurrentNet() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print the MAC address of the router you're attached to:
  byte bssid[6];
  WiFi.BSSID(bssid);    
  Serial.print("BSSID: ");
  Serial.print(bssid[5],HEX);
  Serial.print(":");
  Serial.print(bssid[4],HEX);
  Serial.print(":");
  Serial.print(bssid[3],HEX);
  Serial.print(":");
  Serial.print(bssid[2],HEX);
  Serial.print(":");
  Serial.print(bssid[1],HEX);
  Serial.print(":");
  Serial.println(bssid[0],HEX);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.println(rssi);

  // print the encryption type:
  byte encryption = WiFi.encryptionType();
  Serial.print("Encryption Type:");
  Serial.println(encryption,HEX);
  Serial.println();
}

No, the WiFi library is written for the Arduino WiFi Shield, not the Yun. You need to use the Bridge library for the Yun. See:
https://www.arduino.cc/en/Reference/YunBridgeLibrary
and File > Examples > Bridge.

Alright. Thanks!

See my other post, below.

I made the same mistake of trying to run Yun Shield code on the Yun.

Look at this example to run pretty-wifi… across the bridge on the Linux side of your Yun…