Fornext cycles?
Hi everyone!
Here’s a little (part of) shader:
uniform int numLights // ?
void main()
{
....
// Light 0:
float LightAttenuation0 = clamp(1.0  dot(g_light0Vec, g_light0Vec), 0.0, 1.0);
vec3 light0Vec = normalize(g_light0Vec);
float diffuse0 = clamp(dot(light0Vec, bump), 0.0, 1.0);
float specular0 = pow(clamp(dot(reflect(viewVec, bump), light0Vec), 0.0, 1.0), 16.0);
float l0 = gl_LightSource[0].diffuse * (diffuse0 * base + 0.3 * specular0)
* LightAttenuation0;
// Light 1 (the same as for Light 0, just place 1 instead of 0):
float LightAttenuation1 = clamp(1.0  dot(g_light1Vec, g_light1Vec), 0.0, 1.0);
vec3 light1Vec = normalize(g_light1Vec);
float diffuse1 = clamp(dot(light1Vec, bump), 0.0, 1.0);
float specular1 = pow(clamp(dot(reflect(viewVec, bump), light1Vec), 0.0, 1.0), 16.0);
float l1 = gl_LightSource[1].diffuse * (diffuse1 * base + 0.3 * specular1)
* LightAttenuation1;
// Light 2 (the same as for Light 0, just place 2 instead of 0):
float LightAttenuation2 = clamp(1.0  dot(g_light2Vec, g_light2Vec), 0.0, 1.0);
vec3 light2Vec = normalize(g_light2Vec);
float diffuse2 = clamp(dot(light2Vec, bump), 0.0, 1.0);
float specular2 = pow(clamp(dot(reflect(viewVec, bump), light2Vec), 0.0, 1.0), 16.0);
float l2 = gl_LightSource[2].diffuse * (diffuse2 * base + 0.3 * specular2)
* LightAttenuation2;
// Result:
gl_FragColor = color_base * (l0 + l1 + l2);
}
Two questions here:

How can I avoid repeating code blocks for different lights? Can I use arrays(are there any in GLSL?) and forcycles?
All I wish is to control the shader with numLights variable. 
The result line:
gl_FragColor = color_base * (l0 + l1 + l2);
Is it ok to add light contribuitions that way?
Thanks in advance,
Dmitry.