[SamuraiBarbi]

Can I get away with doing something like

register_event("Sentry_Built_Level_1", "sentry_built", "be")
register_event("Sentry_Upgrade_Level_2", "sentry_lvltwo", "be")
register_event("Sentry_Upgrade_Level_3", "sentry_lvlthree", "be")

to hook events related to sentry guns?

[schnitzelmaker]

Afaik its not possible.
But you can use an Soundhook to get these events.

Here an Example(untested):

#include <amxmodx>
#include <amxmisc>
#include <fakemeta>


#define PLUGIN "New Plug-In"
#define VERSION "1.0"
#define AUTHOR "Administrator"


public plugin_init() {
    register_plugin(PLUGIN, VERSION, AUTHOR)
    
    register_forward(FM_EmitSound, "fw_EmitSound")  
}

public fw_EmitSound(id, channel, sample[])
{
    if(!strcmp(sample,"weapons/turrset.wav") && pev_valid(id) && id > 32)
    {
        new classname[32]
        pev(id,pev_classname,classname,31)
        if (!strcmp(classname,"building_dispenser"))
            client_print(0,print_chat,"Dispencer Builded")
        else if (!strcmp(classname,"building_sentrygun"))
        {
            new sentry_level = get_pdata_int(id,37,3)//offset 37 hold sentry level(+3 for linux offset)
            if (sentry_level == 1)
                client_print(0,print_chat,"Sentrygun Builded")
            else if (sentry_level == 2)
                client_print(0,print_chat,"Sentrygun Upgraded to Level2")
            else if (sentry_level == 3)
                client_print(0,print_chat,"Sentrygun Upgraded to Level3")
        }
        else if (!strcmp(classname,"building_teleporter"))
        {
            new teleporter_type = get_pdata_int(id,427) //offset 427 hold the type of teleporter(entrance=4,exit=5)
            if (teleporter_type == 4)
                client_print(0,print_chat,"Entrance Teleporter builded")
            else client_print(0,print_chat,"Exit Teleporter builded")
        }
    }
    return FMRES_IGNORED
}