Suck the life out of them, literally tutorial - Quake 2

[page=Starting]
Open your compiler, and get open your source files!

[page=Command]

Open g_cmds.c, and head right to the bottom.

After

else if (Q_stricmp (cmd, "wave") == 0)
        Cmd_Wave_f (ent);

Add:

else if (Q_stricmp (cmd, "drop") == 0)
        Suck (ent);

Also, at the top of the page after the includes, add:

void parasite_drain_attack (edict_t *self);

Now, add this before void ClientCommand:

void Suck(edict_t *ent) 
{
        vec3_t end,forward;
        trace_t tr;
 
        VectorCopy(self->s.origin,end);
        AngleVectors (ent->client->v_angle, forward, NULL, NULL);
        end[0]=end[0]+forward[0]*250;
        end[1]=end[1]+forward[1]*250;
        end[2]=end[2]+forward[2]*250;
 
        tr = gi.trace (ent->s.origin, NULL, NULL, end, ent, MASK_SHOT);
        if(tr.ent != NULL) 
        {
               ent->enemy=tr.ent;
               parasite_drain_attack(ent);
        }
}

Also, another thing you may want to do is get health for the attack. Head to the function parasite_drain_attack, and under T_Damage, add:

self->health=self->health+damage;

Mind you, It's something I threw together, I have not tested it myself. Check it and mail me the results, I will test it in a days time.