I have a problem using Paho MQTT client in C.
I downloaded the pre built binaries for my system (Windows 10 64) from their projects page. I unpacked the zip file to a folder in the documents folder, where I also created a .c file with the example at the bottom of the Paho product page. My editor is atom and my compiler is gcc.
When I tried to compile it in Atom, I got this error:
undefined reference to MQTTClient_create'
So I went searching and found plenty of topics, but I still couldn't figure out, how to resolve this issue. From this stackoverflow topic I gather that it's a linker problem and that I need to link the files during compile, so here's what I tried:
gcc MQTT.c -L "C:\Users\Pete\Documents\MQTT on C\Examples\Paho\lib" -l paho-mqtt3c
Which still gives me the same undefined reference error. When I try to link to the dll of the same name, the compiler does not find the file.
Can anyone point me in the right direction, please?
Any help is appreciated!
I'd be interested to know if you have registered the Paho MQTT dll in Windows?
You should have paho-mqtt3c.dll as part of the download.
I don't know if this will work for you, but I have the same issue (undefined reference to MQTTClient_create)...
Copy the dll file into c:/windows/system32
Run CMD Prompt as Administrator and type:
regsvr32 i/ paho-mqtt3c.dll
Worth a try.
The problem was that I was compiling the program with the 32-bit gcc compiler for the 64-bit library. Installing and using MinGW64 worked.
I had the same issue in OS X. This is how I resolved it
I compiled the paho-mqtt library in Linux/EC2 instance.
Installed all the dependencies:
sudo yum install install build-essential gcc make cmake cmake-gui cmake-curses-gui
sudo yum install cmake
sudo yum install doxygen graphviz
cmake -DPAHO_WITH_SSL=TRUE -DPAHO_BUILD_DOCUMENTATION=FALSE -DPAHO_BUILD_STATIC=TRUE -DPAHO_BUILD_SHARED=FALSE -DPAHO_MQTT_C_PATH=../paho.mqtt.c/ -DPAHO_MQTT_C_LIB=../paho.mqtt.c/src/libpaho.mqtt3as-static.a
make
make html
make install
LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/ec2-user/paho.mqtt.c/src
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH
sudo ldconfig
gcc test1.c -o test1 -lpaho-mqtt3c
Compiled successfully..
./test1
This solution works for OS X as well. Replace step 2 with
brew install cmake doxygen openssl-devel
Related
I am trying to install the MPI FFTW2 libraries (fftw2.1.5) as I need them for a program that only works with that version. The specific library I need is "drfftw_mpi.h" so I try the followed:
./configure --enable-mpi --enable-type-prefix
But it always gives me the following error:
configure: error: couldn't find mpi library for --enable-mpi
In a previous question they solve it by running sudo ldconfig before, but for me it does not work giving the same error. For other mpi software they solve it in this post by passing mpicc as the right compiler to ./configure, with the CC flag CC=mpicc, something that does not work for me.
I have installed Open MPI version 4.0.3 on a Ubuntu 20.04 LTS, and when --enable-mpi is not used I was able to install "dfftw.h" "drfftw.h" "fftw.h" and "rfftw.h", do you have an idea of what I am doing wrong or what should I do to install "drfftw_mpi.h"?
I followed NSS build instructions and built NSS successfully.
Then I follow JSS build instructions and building fails with error:
In file included from CryptoManager.c:6:0:
../../../../dist/public/nss/secitem.h:15:21: fatal error: plarena.h: No such file or directory
compilation terminated.
This result is on Ubuntu 16.04 LTS.
On WIndows I get:
All directories (dist, jss, nspr and nss) are on the same level.
What am I doing wrong?
Check my post here. Basically it's due to missing packages. If not working, this file is somewhere under nspr. Copy it and place it beside the .c file which needs it.
EDIT:
To sum it up:
1. Install build-essential and gcc with g++.
2. Try to install zlib1g-dev and libc6-dev, if they are absent.
3. And, install zlib1g-dev.
4. cd into the nss directory, and run the build like this:
gmake nss_build_all NSS_SSL_ENABLE_ZLIB=
if you are under a x64 environment, add USE_64=1, too.
It should work.
I am new to Cassandra. I installed c++ driver from Datastax. Can some one please provide me the steps like in which path I have to create the ‘.c’ file and how I can compile it. I can see some example programs in example folder. Can anyone plz tell me how to compile the example programs.
The cpp-driver uses cmake and depends on libuv. So the first steps would be to ensure you have cmake installed as well as libuv. Depending on your linux distribution it may be as simple as using package manager like apt or yum (i.e. sudo apt-get install cmake libuv-dev)
Building is just a matter of running the following steps in the cpp-driver directory:
cmake .
make
sudo make install
This will install libcassandra.so to somewhere in your lib path. You can then link by providing '-lcassandra' in your parameters to clang or gcc (i.e. clang myfile.c -o myfile -lcassandra)
There is very comprehensive documentation on building from source here.
While building gcc, I get this error:
In file included from /usr/include/bits/errno.h:25,
from /usr/include/errno.h:36,
from ../.././gcc/tsystem.h:96,
from ../.././gcc/crtstuff.c:68:
/usr/include/linux/errno.h:4:23: error: asm/errno.h: No such file or directory
make[2]: *** [crtbegin.o] Error 1
make[2]: Leaving directory `/opt/gcc-4.1.2/host-x86_64-unknown-linux-gnu/gcc'
I am building gcc 4.1 from source. I think I have to install build-essential. However installing that package in ubuntu 12.04 will automatically download and install gcc 4.6 and I don't want that.
Is there any other way?
I think the package you want is linux-libc-dev . I encountered this when building 32-on-64; so I needed linux-libc-dev:i386 .
This worked for me:
ln -s /usr/include/asm-generic /usr/include/asm
This worked for me:
sudo ln -s /usr/include/asm-generic /usr/include/asm
The reason being that what GCC expects to be called /usr/include/asm is renamed to /usr/include/asm-generic in some distros.
This fixed it for me.
sudo apt-get install linux-libc-dev:i386
This solved it for me on Debian 10, even though I was compiling with an LLVM-based compiler:
sudo apt install gcc-multilib
/usr/include/asm/errno.h is part of the linux headers. I can't speak directly to Ubuntu 12.04, but in general you can download the linux sources as a package for your distro and it shouldn't require you to download/install gcc. Failing that, you can manually download the linux headers for the version of your kernel (uname -a) and use an include directive to CFLAGS to specify the directory to look for those.
Edit: sudo apt-get install linux-headers-generic may work for you.
You are missing part of the development packages. I don't know Ubuntu, but you should be able to ask it's package management system to install the package containing /usr/include/asm/errno.h.
Do not copy some file with a similar name from somewhere on your system (or, even worse, from somewhere else). Missing files might mean that some package is damaged; again, ask your package manager to check everything and (re)install missing/broken pieces.
Unless you are running some LTS release, upgrade. Your Ubuntu is some 2 years old, i.e., ancient.
While we are at this, why on this beautiful planet are you building such an ancient compiler? Current GCC is just released 4.9.0, anything before 4.7 is ancient history, not longer supported.
On Ubuntu 16.04 x86_64 you could try this:
ln -s /usr/include/x86_64-linux-gnu/asm /usr/include/asm
This works on my server.
If you want to use errno.h that is in the asm file, simply go to /usr/(ctrl + l, type /usr/) and then search for errno.h and errno-base.h. Once you did find them, copy the code in these two files, and place them in your include folder. And be careful, in "errno.h" the file includes "errno-base.h" as:
#include <asm-generic/errno-base.h>
Either create a directory with the same name above or change the code above to something different which is suitable for you to use.
If you can find:
usr/include/asm-generic/errno.h
by executing:
find /usr/include -name errno.h
then try to execute:
cp --archive /usr/include/asm-generic /usr/include/asm
It may fix that problem.
I had this issue while compiling Asterisk 1.8.24.0 and solved it with:
mkdir /usr/include/asm-generic
cp /usr/include/asm/errno-base.h /usr/include/asm-generic/
Don't know if it is the "right way" but i've read the comments above and that gave me the idea... and it worked :)
I'm trying to build GCC 4.6 under CentOS release 5.5 (Final). I've freshly built GMP-5.0.1, MPC-0.9, and MPFR-3.0.1, and have used the following configure command:
../configure --prefix=/users/xxxx/apps/mygcc4.6 --disable-checking --enable-threads=posix --enable-languages=c,c++,fortran --with-mpfr=/users/xxxx/code/gcc/mpfr-3.0.1-install-cyprus --with-gmp=/users/xxxx/code/gcc/gmp-5.0.1-install-cyprus --with-mpc=/users/xxxx/code/gcc/mpc-0.9-install-cyprus
After this, I run make and after about 5 minutes get the following error message:
checking for suffix of object files... configure: error: in /users/xxxx/code/gcc/gcc-4.6.0/obj/x86_64-unknown-linux-gnu/libgcc':
configure: error: cannot compute suffix of object files: cannot compile
Seeconfig.log' for more details.
The config.log indicates that a recently generated program (cc1) is involved:
/users/xxxx/code/gcc/gcc-4.6.0/obj/./gcc/cc1
Indeed if I run this program with no arguments I get the same error message found in config.log:
error while loading shared libraries: libmpfr.so.4: cannot open shared object file: No such file or directory
However, libmpfr.so.4 is in the lib subdirectory of that provided to configure using the --with-mpfr flag, as seen above. I have LD_LIBRARY_PATH and LIBRARY_PATH empty. Any idea how I can get past this error?
Make sure your library is acutally in the directory given and not in some lib subdirectory. Use export LD_LIBRARY_PATH=/users/xxxx/code/gcc/mpfr-3.0.1-install-cyprus as you have already suggested ;-)
I know this thread is pretty outdated. But, I had to comment and say that after 5+ hours of banging my head against the wall on a very similar issue (checking for suffix of object files... configure: error: cannot compute suffix of object files: cannot compile) and having read the install manual, a multitude of forums, and trying various things on the system in question I found this brief but very useful post. The issue was precisely related to LD_LIBRARY_PATH.
Long story short, when building from source if you hit this wall export the LD_LIBRARY_PATH variable to point into the source build directory for the libs.
Worked for me anyway.
Good luck folks.
I know that this thread is pretty outdated. I faced similar issues while installing mpfr on WSL. The build was fine and mpfr installed correctly but when I wrote a small C file to see if I could access the header file and print the version fo the installation - I could compile the C file but When I tried to run the compiled object - it would give me an error. The C file was,
#include <stdio.h>
#include <mpfr.h>
int main (void) {
printf ("MPFR library: %-12s\nMPFR header: %s (based on %d.%d.%d)\n",
mpfr_get_version (), MPFR_VERSION_STRING, MPFR_VERSION_MAJOR,
MPFR_VERSION_MINOR, MPFR_VERSION_PATCHLEVEL);
return 0;
}
I was compiling this with,
gcc -o version mpfr_presence.c -lmpfr -lgmp
But when I tried to run this with ./version, I would get the following error,
./version: error while loading shared libraries: libmpfr.so.6: cannot open shared object file: No such file or directory
I solved this error using,
sudo apt-get update
sudo apt-get install libmpfr4
And then when it said that libmpfr4 was already at its latest version, just to be sure,
sudo apt-get install --reinstall libmpfr4
Now ./version gives me,
MPFR library: 4.0.1
MPFR header: 4.0.1 (based on 4.0.1)