Zabbix Script on Agent Executes Correctly, but returns empty value

[netkey]

Hello，

Using 3.4.1，I have writed my custom traceroute script named tgmtr,which is hacked from system traceroute, it can show the ip info like geoip,it can run correctly on agent like this:

[zabbix@tg36 ~]$ tgmtr -q 1 -n 122.227.42.233
traceroute to 122.227.42.233 (122.227.42.233), 30 hops max, 60 byte packets
1 61.134.34.33 陕西省宝鸡市电信 0.451 ms
2 61.134.34.173 陕西省宝鸡市明乐网吧 0.544 ms
3 219.145.131.41 陕西省宝鸡市电信 0.890 ms
4 219.145.131.9 陕西省宝鸡市电信 3.145 ms
5 *
6 220.188.121.2 浙江省金华市电信 32.849 ms
7 *
8 *
9 122.227.42.233 浙江省金华市电信 37.211 ms

And I add a custom item in the userparams.conf:
UserParameter=net.icmp.mymtr[*],tgmtr -q 1 -n $1

when I run the command on the zabbix server

#/usr/local/zabbix/bin/zabbix_get -s 61.134.34.36 -k net.icmp.mymtr[122.227.42.233]

it returns empty value,and the zabbix_agentd.log shows:

77032:20170921:105643.945 In zbx_popen() command:'tgmtr -q 1 -n 122.227.42.233'
77032:20170921:105643.958 Run remote command [tgmtr -q 1 -n 122.227.42.233] Result [0] []...

But when I use the system traceroute instead of my tgmtr,it works fine!

UserParameter=net.icmp.mymtr[*],traceroute -q 1 -n $1

#/usr/local/zabbix/bin/zabbix_get -s 61.134.34.36 -k net.icmp.mymtr[122.227.42.233]
traceroute to 122.227.42.233 (122.227.42.233), 30 hops max, 60 byte packets
1 61.134.34.33 0.444 ms
2 61.134.34.173 0.579 ms
3 219.145.131.41 0.701 ms
4 219.145.131.1 3.403 ms
5 202.97.78.218 29.262 ms
6 220.188.121.30 32.873 ms
7 *
8 *
9 122.227.42.233 37.446 ms

tgmtr is under /usr/sbin like traceroute.
I'm very trouble about this, any suggestions?