Install gflags

gflags, commandline flags module for C++.

Environment

Install gflags.

Download gflags-2.0.tar.gz

$ tar zxvf gflags-2.0.tar.gz
$ cd gflags-2.0
$ ./configure
$ make
$ sudo make install
$ sudo ldconfig
$ cd ..
$ rm -rf gflags-2.0

Code

// gflags_test.cc

#include <iostream>
#include <gflags/gflags.h>

DEFINE_bool(my_bool, false, "bool type");
DEFINE_int32(my_int32, 123, "int32 type");
DEFINE_int64(my_int64, 1245L, "int64 type");
DEFINE_uint64(my_uint64, 12345L, "uint64 type");
DEFINE_double(my_double, 1.234L, "double type");
DEFINE_string(my_string, "init", "string type");

int main(int argc, char** argv) {
  google::ParseCommandLineFlags(&argc, &argv, true);
  std::cout << "my_bool: " << FLAGS_my_bool << std::endl;
  std::cout << "my_int32: " << FLAGS_my_int32 << std::endl;
  std::cout << "my_int64: " << FLAGS_my_int64 << std::endl;
  std::cout << "my_uint64: " << FLAGS_my_uint64 << std::endl;
  std::cout << "my_double: " << FLAGS_my_double << std::endl;
  std::cout << "my_string: " << FLAGS_my_string << std::endl;                                                                       
  return 0;
}

Build

$ g++ gflags_test.cc -lgflags

Test

$ ./a.out 
my_bool: 0
my_int32: 123
my_int64: 1245
my_uint64: 12345
my_double: 1.234
my_string: init
$ ./a.out --my_bool=true --my_int32=234 --my_int64=2345 --my_uint64=23456 \
> --my_double=2.345 --my_string=new
my_bool: 1
my_int32: 234
my_int64: 2345
my_uint64: 23456
my_double: 2.345
my_string: new

References