Produce keyboard Events key hits

Question

How to make a simple C program which will produce keyboard key hits.

if ( condition ) {
    KeyPress('A');
}

I am working on Ubuntu 8.10 Linux OS

Answer 1

Get Fake Key Events by Xdotool

//Compile As:  gcc button.c -lX11 

#include < X11/Xlib.h >
#include < X11/Xutil.h >
#include < stdio.h >
#include < X11/extensions/XTest.h >

void press_button()
{   
    Display *d;
    d = XOpenDisplay(NULL);
        if(d == NULL)
        {
            //fprintf(stderr, "Errore nell'apertura del Display !!!\n");
            //exit(0);
        }
    system("xdotool key Shift+a");
    XFlush(d);
    XCloseDisplay(d);
}

int main() {
    press_button();
    return 0;
}