Add ability to install library and headers through CMake

[whoshuu]

There are three competing pull requests right now that implement this. My laziness has unfortunately resulted in some duplicate work 😥 .

#176
#132
#56

Unbiased discussion on the pros and cons of each approach would be appreciated. The immediate goal is to make make install in a sane way. The long term goal is to make packaging the library (for something like Homebrew for instance) feasible so it can be distributed without git.

[nyorain]

At the moment, there is no (convenient) way to install cpr system-wide which makes it hard to package.
Simply providing install() cmake commands does not help this much since this (as you pointed out in #176) would also install the curl headers and libraries which is bad (might mess up linux package manager if installed in /usr).
They are installed because curl is built using add_subdirectory instad of using a cmake external project or something similar.

But changing this might introduce a couple new problems and makes the whole solution more complex so I am not sure if it is worth it if there is another way (but by doing so it would be possible to switch curl installation via a cmake option I guess).

[apollo13]

Well, installation would still be nice in the cases where for instance system curl is used (which would be done if you wanted to package CPR for debian etc…).

[sim590]

Debian and Archlinux packages would be appreciated nice.

[sroycode]

https://github.com/sroycode/identt/blob/master/src/cpr/CMakeLists.txt
includes cpr as part of a cmake project

[0biWanKenobi]

Dear developer,

I have built CPR successfully, however I have no idea - being quite new to the c\c++ world - how to use it. "sudo make install" just copies curl into usr/local.. I see there are already open issues, so opening one seems to be the wrong way to go about it. Instead, could you provide simple instructions on how to include CPR in one's project? You currently mention git subdirectory and cmakelists, but not everyone has his project under versioning, or is using cmake.

Thanks a lot!

[SamuelKarlos]

You are not finding this include, what should I do?
#include <cpr/cpr.h>

Please, can anyone help me?
I have already added add_subdirectory (cpr) in CMAKE.list and have the following error:

Could not find OpenSSL, try to set the path to OpenSSL root folder in the
system variable OPENSSL_ROOT_DIR (missing: OPENSSL_INCLUDE_DIR)

I have already added openssl to the project, but I can not configure it in CMALKELIST.

[sroycode]

Hi:
Have a look at
https://github.com/sroycode/identt
where CPR is included as a sub-project which you will find in include/cpr
and src/cpr
there is a CMakeLists.txt in src/cpr , you will need these two lines to include curl + openssl in main CMakeLists.txt

find_package(CURL 7.29 REQUIRED)
include_directories(${CURL_INCLUDE_DIRS})
set(YOURPROJECT_LIB_DEPS ${YOURPROJECT_LIB_DEPS} ${CURL_LIBRARIES})

find_package(OpenSSL REQUIRED)
include_directories(${OPENSSL_INCLUDE_DIR})
set(YOURPROJECT_LIB_DEPS ${YOURPROJECT_LIB_DEPS} ${OPENSSL_SSL_LIBRARIES} ${OPENSSL_CRYPTO_LIBRARIES})

Regards
SRC

[SamuelKarlos]

That's awesome! Thank you!

[SamuelKarlos]

Hello, I encountered another problem:
the include does not work: #include <cpr / cpr.h>

Debug Result:

/Applications/CLion.app/Contents/bin/cmake/bin/cmake -DCMAKE_BUILD_TYPE = Debug -G "CodeBlocks - Unix Makefiles" / Users / samuelkarlos / Downloads / testCmake

• Checking compiler flags for C ++ 11 support.

• C ++ 11 is supported.

• C ++ Requests CMake Options

• ================================================================= =======

• USE_SYSTEM_CURL: OFF

• BUILD_CPR_TESTS: ON

• GENERATE_COVERAGE: OFF

• CPR_CURL_NOSIGNAL: OFF

• USE_SYSTEM_GTEST: OFF

• CMAKE_USE_OPENSSL: ON

• ================================================================== =======

• Not using system curl, using built-in curl project instead.
  CMake Warning at cpr / opt / curl / CMakeLists.txt: 50 (message):
    the curl cmake build system is poorly maintained. Be aware

• curl version = [7.56.0-DEV]
  Found * nroff option: - -man

• Could NOT find LibSSH2 (missing: LIBSSH2_INCLUDE_DIR LIBSSH2_LIBRARY)

• Enabled features: OpenSSL IPv6 unix-sockets libz AsynchDNS NTLM

• Enabled protocols: DICT FILE FTP FTPS GOPHER HTTP HTTPS IMAP IMAPS LDAP POP3 POP3S RTSP SMTP SMTPS TELNET TFTP

• Set CURL_FOUND to TRUE.

• Set CURL_LIBRARIES to libcurl.

• Set CURL_INCLUDE_DIRS to / Users / samuelkarlos / Downloads / testCmake / cpr / opt / curl / include; / Users / samuelkarlos / Downloads / testCmake / cpr / opt / curl / include / curl.

• Not using system gtest, using built-in googletest project instead.

• Set GTEST_FOUND to TRUE.

• Set GTEST_LIBRARIES to gtest.

• Set GTEST_MAIN_LIBRARIES to gtest_main.

• Set GTEST_BOTH_LIBRARIES to gtest; gtest_main.

• Set GTEST_INCLUDE_DIRS to / Users / samuelkarlos / Downloads / testCmake / cpr / opt / googletest / include.

• Building mongoose project for test support.

• Set MONGOOSE_FOUND to TRUE.

• Set MONGOOSE_LIBRARIES to mongoose.

• Set MONGOOSE_INCLUDE_DIRS to / Users / samuelkarlos / Downloads / testCmake / cpr / opt / mongoose.

• Using CURL_INCLUDE_DIRS: / Users / samuelkarlos / Downloads / testCmake / cpr / opt / curl / include; / Users / samuelkarlos / Downloads / testCmake / cpr / opt / curl / include / curl.

• Using CURL_LIBRARIES: libcurl.

• Configuring done

• Generating done

• Build files have been written to: / Users / samuelkarlos / Downloads / testCmake

[Finished]

I added add_subdirectory (cpr) to my CMAKELIST.

How to solve this? Please

[SamuelKarlos]

Hello, I was able to solve the above problem, but I came across another problem ...

/Applications/CLion.app/Contents/bin/cmake/bin/cmake --build / Users / samuelkarlos / Downloads / testCmake --target testCmake - -j 4
Scanning dependencies of target testCmake
Building CXX object CMakeFiles / testCmake.dir / src / main.cpp.o
Linking CXX executable testeCmake
Undefined symbols for architecture x86_64:
  "cpr :: Parameters :: Parameters (std :: initializer_list const &)", referenced from:
      _main in main.cpp.o
  "cpr :: Session :: Get ()", referenced from:
      cpr :: Parameters (std :: __ 1 :: allocator ), cpr :: Parameters (std :: __ 1 :: allocator : __ 1 :: basic_string <char, std :: __ 1 :: char_traits , std :: __ 1 :: allocator > &&, cpr :: Parameters &&) in main.cpp.o
  "cpr :: Session :: SetOption (cpr :: Parameters &&)", referenced from:
      void cpr :: priv :: set_option (cpr :: Session &, cpr :: Parameters &&) in main.cpp.o
  "char, std :: __ 1 :: allocator char :: std :: __ 1 :: char_traits , std :: __ 1 :: allocator > const"), referenced from:
      void cpr :: priv :: set_option <std :: __ 1 :: basic_string <char, std :: __ 1 :: char_traits , std :: __ 1 :: allocator > (cpr :: Session &, std: : __ 1 :: basic_string <char, std :: __ 1 :: char_traits , std :: __ 1 :: allocator > &&) in main.cpp.o
  "cpr :: Session :: Session ()", referenced from:
      cpr :: Parameters (std :: __ 1 :: allocator ), cpr :: Parameters (std :: __ 1 :: allocator : __ 1 :: basic_string <char, std :: __ 1 :: char_traits , std :: __ 1 :: allocator > &&, cpr :: Parameters &&) in main.cpp.o
  "cpr :: Session :: ~ Session ()", referenced from:
      cpr :: Parameters (std :: __ 1 :: allocator ), cpr :: Parameters (std :: __ 1 :: allocator : __ 1 :: basic_string <char, std :: __ 1 :: char_traits , std :: __ 1 :: allocator > &&, cpr :: Parameters &&) in main.cpp.o
ld: symbol (s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make [3]: *** [testCmake] Error 1
make [2]: *** [CMakeFiles / testCmake.dir / all] Error 2
make [1]: *** [CMakeFiles / testCmake.dir / rule] Error 2
make: *** [testCmake] Error 2

---

Here is my sample code:

#include
#include "cube.h"
#include <cpr / cpr.h>

int main (int argc, char ** argv) {

    auto r = cpr :: Get (cpr :: url {"http://www.httpbin.org/get"),
                      cpr :: Parameters {{"hello", "world"}});
    std :: cout << r.url << std :: endl; // http://www.httpbin.org/get?hello=world
    std :: cout << r.text << std :: endl;
}

[tolstenko]

Have you tried the hunter approach? It is full CMake approach. https://github.com/ruslo/hunter/tree/master/examples/cpr

[pizzard]

we had to add
install( TARGETS indurad-util DESTINATION lib OPTIONAL )
at the end of the cpr cmake lists and this fixed all our problems.
We do not build curl but just take it from the system.

Can we just add that routine for the case one uses system lib? Because for that case its that easy.

[HarrisDePerceptron]

I do not want a submodule. apparently the proj i am working on has all compiled deps system wide and i do not want just this perticular library as a submodule.

Trying to install system wide:

git clone https://github.com/whoshuu/cpr.git
cd cpr
git submodule update --init opt/curl
cmake -DBUILD_CPR_TESTS=OFF ..
make -j
sudo make install

From the root of the project: cd path/to/project
included this at my root CMakeLists.txt:
find_package(CPR REQUIRED)

mkdir build && cd build 
cmake ..

Gives me an error:

[cmake] CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
[cmake] Could NOT find CPR (missing: CPR_LIBRARY CPR_INCLUDE_DIR)

[jungletek]

I do not want a submodule. apparently the proj i am working on has all compiled deps system wide and i do not want just this perticular library as a submodule.

Trying to install system wide:

git clone https://github.com/whoshuu/cpr.git
cd cpr
git submodule update --init opt/curl
cmake -DBUILD_CPR_TESTS=OFF ..
make -j
sudo make install

From the root of the project: cd path/to/project
included this at my root CMakeLists.txt:
find_package(CPR REQUIRED)

mkdir build && cd build 
cmake ..

Gives me an error:

[cmake] CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
[cmake] Could NOT find CPR (missing: CPR_LIBRARY CPR_INCLUDE_DIR)

It's telling you right there that you're missing two CMake variables in your CMakeLists.txt (root one): CPR_LIBRARY and CPR_INCLUDE_DIR.

So add this before the find() or find_package() or whatever:

set(CPR_INCLUDE_DIR "path_to_cpr_includes") # can be an absolute path, or relative to the project directory
set(CPR_LIBRARY "path_to_CPR_root/cpr")

If you've already set CPR_DIR, then you can just use that macro as a path reference. Mine looks like this:

set(CPR_DIR "cpr-feature-Stream-MOD")
add_subdirectory(${CPR_DIR} ${CPR_DIR} EXCLUDE_FROM_ALL)
set(CPR_INCLUDE_DIR ${CPR_DIR}/include)
set(CPR_LIBRARY ${CPR_DIR}/cpr)
find_package(CPR REQUIRED)

[COM8]

Should be fixed in #645