It's very fast.good! (and how to install)

[zrlhk]

Install tips:

git clone https://github.com/protobuf-c/protobuf-c
apt install –y a utoconf automake libtool protobuf-compiler python3.5-dev
./autogen.sh && ./configure && make && make install

and langid.c: make all

use for file:

cat xxx.en |./langid -l > lan.txt

I use 64 cores CPU
if use langid.py => 3 days
now just less than half an hour

[zrlhk]

apt install -y autoconf automake libtool protobuf-compiler python-dev python3.5-dev pkg-config protobuf-c-compiler

[zrlhk]

don't forget use python2,and:

apt install -y langid autoconf automake libtool protobuf-compiler python-dev python3.5-dev pkg-config protobuf-c-compiler php;pip install protobuf

install protobuf-c:

git clone https://github.com/protobuf-c/protobuf-c
./configure --prefix=/usr/local&& make && make install
./autogen.sh && ./configure && make && make install

then:
cd langid.c;make all