Not able to use bitcoin/bitcoin.hpp

Question

the libbitcoin library seems to have been installed just fine. but the following code can't seem to include bitcoin/bitcoin.hpp

#include<bitcoin/bitcoin.hpp>
#include<iostream>
using namespace bc;
int main() {
    block_type blk = genesis_block();
    std::cout<<encode_hex(hash_block_header(blk.header))<<std::endl;
    return 0;
}

Error:

g++ -o test test.cpp $(pkg-config --cflags --libs libbitcoin)
test.cpp: In function ‘int main()’:
test.cpp:5:5: error: ‘block_type’ was not declared in this scope
     block_type blk = genesis_block();
     ^~~~~~~~~~
test.cpp:5:5: note: suggested alternative: ‘clock_t’
     block_type blk = genesis_block();
     ^~~~~~~~~~
     clock_t
test.cpp:6:45: error: ‘blk’ was not declared in this scope
     std::cout<<encode_hex(hash_block_header(blk.header))<<std::endl;
                                             ^~~
test.cpp:6:45: note: suggested alternative: ‘brk’
     std::cout<<encode_hex(hash_block_header(blk.header))<<std::endl;
                                             ^~~
                                             brk
test.cpp:6:27: error: ‘hash_block_header’ was not declared in this scope
     std::cout<<encode_hex(hash_block_header(blk.header))<<std::endl;
                           ^~~~~~~~~~~~~~~~~
test.cpp:6:16: error: ‘encode_hex’ was not declared in this scope
     std::cout<<encode_hex(hash_block_header(blk.header))<<std::endl;
                ^~~~~~~~~~

Answer 1

I was able to run this code:

#include <bitcoin/bitcoin.hpp>

int main() 
{
  bc::ec_secret decoded;
  bc::decode_base16(decoded, "038109007313a5807b2eccc082c8c3fbb988a973cacf1a7df9ce725c31b");
}

Follow this https://github.com/libbitcoin/libbitcoin#debianubuntu

After compile it in a /home/x/dir run this:

g++ helloworld.cpp -I/home/dev/bitcoin-lib/include /home/dev/bitcoin-lib/lib/libbitcoin.a /home/dev/bitcoin-lib/lib/libboost_system.a /home/dev/bitcoin-lib/lib/libbitcoin.a /home/dev/bitcoin-lib/lib/libboost_program_options.a /home/dev/bitcoin-lib/lib/libboost_regex.a

• we need to tell g++ where are the headers for our #include statement
• We need to tell g++ what are the libraries: libbitcoin.a, etc

Answer 2

Try adding the -std=c++11 flag.

I had the same problem and the following worked for me:

g++ -std=c++11 -o test test.cpp $(pkg-config --cflags --libs libbitcoin)

Answer 3

The book code examples has an accompanying actively maintained github repo here. However, extra care is needed for the libbitcoin library dependency as it has new breaking changes. For example, #include <bitcoin/bitcoin.cpp> has been rename to #include <bitcoin/system.hpp>. And no more bc::ec_point. It is possible to install an older compatible version of libbitcoin library, but I prefer to use the latest version and made some adjustment in addr.cpp example code.

I manually build and installed the libbitcoin library to a custom location as suggested:

mkdir -p /opt/my/libbitcoin/
$ wget https://raw.githubusercontent.com/libbitcoin/libbitcoin/version3/install.sh
$ chmod +x install.sh
$ ./install.sh --prefix=/opt/my/libbitcoin/ --build-boost --disable-shared

The way I now build addr.cpp is thus:

export PKG_CONFIG_PATH=/opt/my/libbitcoin/lib/pkgconfig/
g++ -o addr addr.cpp $(pkg-config --cflags --libs libbitcoin-system) -lgmp

And then, running the executable:

$ ./addr
Public key: 0202a406624211f2abbdc68da3df929f938c3399dd79fac1b51b0e4ad1d26a47aa
Address: 1PRTTaJesdNovgne6Ehcdu1fpEdX7913CK