Since Uno and Mega has no Serial, replace Serial with Console at Bridge Sample IDE code

/*
  Running process using Process class.

 This sketch demonstrate how to run linux processes
 using an Arduino Yún.

 created 5 Jun 2013
 by Cristian Maglie

 This example code is in the public domain.

 http://www.arduino.cc/en/Tutorial/Process

 To see the Console, pick your Yún's name and IP address in the Port menu
 then open the Port Monitor. You can also see it by opening a terminal window
 and typing
 ssh root@ yourYunsName.local 'telnet localhost 6571'
 then pressing enter. When prompted for the password, enter it.

 */
#include <Console.h>
#include <Process.h>

void setup() {
  // Initialize Bridge
  Bridge.begin();

  // Initialize Serial
  //Serial.begin(9600);

  // Wait until a Serial Monitor is connected.
  //while (!Serial);
  Console.begin();
  while (!Console) {
    ; // wait for Console port to connect.
  }

  // run various example processes
  runCurl();
  runCpuInfo();
}

void loop() {
  // Do nothing here.
}

void runCurl() {
  // Launch "curl" command and get Arduino ascii art logo from the network
  // curl is command line program for transferring data using different internet protocols
  Process p;		// Create a process and call it "p"
  p.begin("curl");	// Process that launch the "curl" command
  p.addParameter("-k");
  p.addParameter("https://www.arduino.cc/asciilogo.txt"); // Add the URL parameter to "curl"
  p.run();		// Run the process and wait for its termination

  // Print arduino logo over the Serial
  // A process output can be read with the stream methods
  while (p.available() > 0) {
    char c = p.read();
    //Serial.print(c);
    Console.print(c);
  }
  // Ensure the last bit of data is sent.
  //Serial.flush();
  Console.flush();
}

void runCpuInfo() {
  // Launch "cat /proc/cpuinfo" command (shows info on Atheros CPU)
  // cat is a command line utility that shows the content of a file
  Process p;		// Create a process and call it "p"
  p.begin("cat");	// Process that launch the "cat" command
  p.addParameter("/proc/cpuinfo"); // Add the cpuifo file path as parameter to cut
  p.run();		// Run the process and wait for its termination

  // Print command output on the Serial.
  // A process output can be read with the stream methods
  while (p.available() > 0) {
    char c = p.read();
    //Serial.print(c);
    Console.print(c);
  }
  // Ensure the last bit of data is sent.
  //Serial.flush();
  Console.flush();
}