I can't run shell commands on Linux through AVR sketch (Arduino Yun)
There's a few things wrong with your program, some more obvious than others.
First, you have to put each parameter to your shell command in a separate addParameter() call. Otherwise it treats all the parameters as a single parameter and tries to connect you to an address of 192.168.1.15 9911 instead of to port 9911 of address 192.168.1.15.
Secondly you should use runAsynchronously() instead of run() otherwise your sketch blocks at that point until nc terminates. If that never happens then your sketch never gets to the point where it can read the data.
Here is an adaption of your sketch that works for me:
#include &lt;Process.h&gt;

Process p;

void setup() {
    Bridge.begin();
    Console.begin();
    p.begin(&quot;nc&quot;);
    p.addParameter(&quot;192.168.1.15&quot;);
    p.addParameter(&quot;9911&quot;);
    p.runAsynchronously();
}

void loop() {
    static uint32_t ts = millis();

    if (millis() - ts &gt; 1000) {
        Console.println(millis());
        ts = millis();
    }

    if (p.running()) {
        while (p.available()) {
            Console.write(p.read());
        }
    } else {
        Console.println(&quot;Restarting process&quot;);
        delay(100);
        p.begin(&quot;nc&quot;);
        p.addParameter(&quot;192.168.1.15&quot;);
        p.addParameter(&quot;9911&quot;);
        p.runAsynchronously();
    }
}

It also re-runs nc if / when it terminates. There's also a &quot;heartbeat&quot; printing of millis() so that you can see the sketch is running.  It uses the console, not Serial, for its output, so SSH in to the Yun and telnet localhost 6571 to view the output.