On my raspberry pi I am using c++ to write a web project. I am following C++ CGI. I installed gnu's cgi library using apt-get installed libcgicc3. When I compile the form g++ -o cform.cgi cform.cpp i am getting the following error. Fatal error cgicc/CgiDefs.h no such file. How do I find the cgi library. I have seen an example of the compile g++ -o file.cgi file.cpp /usr/libcgicc.a that doesn't work for me. libcgicc.a is not in that directory. Where can I find the file to compile the application.
You're almost there. You need to install the libcgicc-dev package instead, that containers header files and the library to link to.
To link with the library (called libcgicc.so):
g++ -o file.cgi file.cpp -lcgicc
Related
I am trying to cross-compile Windows software on Linux using mingw32-w64 and running it with wine. However wine cannot load the libstdc++-6.dll library file. I searched online and found out that you have to put the directory that contains the DLL file into the path registry. In my case, that directory is Z:\bin\i686-w64-mingw32\bin.
Then I tried to run the compiled file by using wine executable.exe and the output is:
0100:err:module:import_dll Loading library libstdc++-6.dll (which is needed by L"Z:\\home\\sunnymonster\\dev\\c++\\opengl-tests\\cmake-build-debug\\opengl_tests.exe") failed (error c000007b).
0100:err:module:LdrInitializeThunk Importing dlls for L"Z:\\home\\sunnymonster\\dev\\c++\\opengl-tests\\cmake-build-debug\\opengl_tests.exe" failed, status c0000135
I have verified that I am using the correct wine prefix.
Additional information:
Linux distro: Manjaro Linux 21.2.5
Linux kernel: 5.16.14-1
There're multiple approaches. First, let's formalize the problem:
$ cat test.cpp
#include <iostream>
int main() { std::cout << "hello" << std::endl; }
$ i686-w64-mingw32-g++ test.cpp -o a && WINEDEBUG=-all,err+module wine ./a.exe
0024:err:module:import_dll Library libgcc_s_dw2-1.dll (which is needed by L"Z:\\tmp\\a.exe") not found
0024:err:module:import_dll Library libstdc++-6.dll (which is needed by L"Z:\\tmp\\a.exe") not found
0024:err:module:LdrInitializeThunk Importing dlls for L"Z:\\tmp\\a.exe" failed, status c0000135
Solutions:
Link the core libraries statically:
$ i686-w64-mingw32-g++ test.cpp -o a -static-libgcc -static-libstdc++ -Wl,-Bstatic -lstdc++ -lpthread -Wl,-Bdynamic
$ WINEDEBUG=-all,err+module wine ./a.exe
hello
Use WINEPATH env. variable to tell wine the additional paths to load dlls from. In the example I pass it the location with mingw dlls that wine complains about. It may be different on your system, you might find it by asking package manager to list files in mingw-g++/gcc packages (whatever it's called on your system). Multiple paths should be separated by semicolon.
$ i686-w64-mingw32-g++ test.cpp -o a
$ WINEDEBUG=-all,err+module WINEPATH=/usr/i686-w64-mingw32/sys-root/mingw/bin/ wine ./a.exe
hello
Install a Windows version of MinGW, and then use it to compile the app. However, from what I remember, if you want to distribute the executable produced, you still need to either statically link against MinGW libs, or provide them together with the binary. So the only difference to point 1 is that the binary should work under your WINEPREFIX with no modifications.
Using wineg++. I mention it solely for completeness, I think it's the least useful solution. It produces a Linux file, which in itself might be okay, one could use that for debugging. However, in my tests, I didn't manage to makewineg++ link against a dll, even though mingw links to the same dll without a problem. It seems to link against .so files instead, even though the application you build with it can load .dll files dynamically. Odd utility.
$ wineg++ test.cpp -o a
$ WINEDEBUG=-all,err+module wine ./a.exe
hello
I have 2 cpp files(with one main function) in /home/misha/proga/c++again folder. I built C/C++: g++ build active task and modified it to compile all files in the folder above. Now, I need to add one more task to call a binary. I think I should add one more entry in "tasks" to finally be able to run a code. Where can I read about how to write this second task? I am new to programming. Is my approach correct to run this code contained in two files? I also do not know where this binary lies. Is it tasks file in .vscode folder ?
I use Ubuntu 19.10 and VSC 1.46.1
In Terminal,
cd /home/misha/proga/c++again
Let's suppose your two cpp files are mainFile.cpp and file2.cpp
If g++ (so GCC) was not installed in your system, you can install it by running this command on the Terminal:
sudo apt-get install gcc g++
and, to compile the program (read about invoking GCC, you want warnings and debug information), write this command into the Terminal:
g++ -Wall -g mainFile.cpp file2.cpp -o yourprog
Then, you can run the program by typing:
./yourprog
It should work now. You could need to use the GDB debugger and GNU make (to be installed with sudo apt-get install gdb make)
Read also some C++ programming book and this C++ reference.
I do not understand your approach usualy your create a makefile and compile your cpp files
g++ -g -c -fpic -o name.o
at the end you link them
g++ name.o 2name.o and so on
If you create binarys you should store them in /usr/lib
and the name should libname.so you can acces them by using the -l argument
I am running LXLE on an Oracle VirtualBox computer. I have successfully installed gumbo for python, but I cannot find how to install the gumbo library for C++, so that if I have a C++ file that includes gumbo.h in the headers, it will actually run.
I am trying to compile a file called countWordsInSite_iterative.cpp using the following command:
g++ countWordsInSite_iterative.cpp -o countWordsInSite -lcurl -lgumbo -g
I get the following error:
countWordsInSite_iterative.cpp:32:10: fatal error: gumbo/gumbo.h: No such file or directory
#include <gumbo/gumbo.h> // For HTML parser
How can I install the necessary files to include gumbo.h?
I originally wanted to compile SQLCipher statically since it seems like it is easier to link up, but I have been unsuccessful at that. The only place I can find that discusses compiling SQLCipher on OS X is this blog post, but even he was not able to get the static compiling to work.
I was able to get the dynamic compiling working for the SQLCipher and I am able to use the sqlcipher command line program as mentioned in the blog, but now I want to use sqlcipher in a compiled C++ program. I have never dealt directly with dynamic compiling in the command line so I am a bit lost.
It looks like it produces a libtool file libsqlcipher.la so I am wondering how I should import it in C++ #include "libsqlcipher.h"? Looking around at tutorials for libtool they mostly mention how to compile it but I have not found any simple examples of how to link it.
I attempted something like this based on what I saw but I got a couple of errors:
libtool g++ -o test EncryptDatabases.cpp sqlcipher/libsqlcipher.la
error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: can't open file: g++ (No such file or directory)
error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: file: EncryptDatabases.cpp is not an object file (not allowed in a library)
error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: file: sqlcipher/libsqlcipher.la is not an object file (not allowed in a library)
Not an answer yes, but too long for a comment.
As far as I remember first libtool should be explicitly told to compile source file into a "library object":
libtool --mode=compile g++ -c EncryptDatabases.cpp -o EncryptDatabases.lo
then it should link the binary:
libtool --mode=link g++ -o test EncryptDatabases.lo sqlcipher/libsqlcipher.la
See the docs
I'm trying to call R from c++ on linux via RInside, I compiled R-2.15.1 from source with gcc version 4.5.3 (Debian 4.5.3-1) , I don't have sudo rights to use apt-get install. I'm using OpenBlas and a system optimized lapack. The blas and lapack libraries work fine for many scalapack applications
I installed R with
./configure --with-blas="-I/lib/OpenBLAS-v0.2.3-0/xianyi-OpenBLAS-48f075c/install/include -L/lib/OpenBLAS-v0.2.3-0/xianyi-OpenBLAS-48f075c/install/lib -lopenblas -lgfortran" --with-lapack="/usr/lib/liblapack.so -lgfortran" --enable-BLAS-shlib=yes --enable-R-shlib --enable-R-static-lib --prefix= .
which installed and runs fine,I ran make check with no errors, also all the packages (Rcpp and RInside) installed fine..
however when i use the given RInside makefile , the basic hello world example from /standard/rinside_sample0.cpp compiles! but it does not run and i get the following error
./rinside_sample0: error while loading shared libraries: libRblas.so: cannot open shared object file: No such file or directory
the file libRblas.so exists and is in the R/lib folder,
when i try to link it manually with the g++ command the make file creates or linking as follows i get a segmentation fault
/R/lib/libRblas.so ./hello_world
Segmentation fault
EDIT: heres how the example make file tries to compile an example, (which compiles fine) but won't run with the above missing libRblas.so error
g++ -I/nfs/user03/jimmie21/libs/lib64/R/include -I/nfs/user03/jimmie21/libs/lib64/R/library/Rcpp/include -I/nfs/user03/jimmie21/libs/lib64/R/library/RInside/include -g -O2 -Wall -I/usr/local/include hello_world.cpp -L/nfs/user03/jimmie21/libs/lib64/R/lib -lR -L/nfs/user03/jimmie21/libs/lib64/R/lib -lRblas -L/nfs/user03/jimmie21/libs/lib64/R/lib -lRlapack -L/nfs/user03/jimmie21/libs/lib64/R/lib -lRblas -L/nfs/user03/jimmie21/libs/lib64/R/library/Rcpp/lib -lRcpp -Wl,-rpath,/nfs/user03/jimmie21/libs/lib64/R/library/Rcpp/lib -L/nfs/user03/jimmie21/libs/lib64/R/library/RInside/lib -lRInside -Wl,-rpath,/nfs/user03/jimmie21/libs/lib64/R/library/RInside/lib -o hello_world
Couple of things:
Reproducible examples, please
You have a non-standard setup
With the script from 1), try it on a standard setting as that is how Rcpp / RInside get developed and tested (on Ubuntu / Debian)
The Rcpp test suite now contains almost 800 unit tests from around 350 unit test functions. These do not seg.fault, so the issue is at your end. Similarly, RInside has dozens of examples in the four examples/ subdirectories. This also works.
It may be as easy as tweaking the Makefile / Makevars files to make sure you get your libraries in all cases. But we can't tell as there is nothing reproducible here.
Edit If you want to link with libRblas.so then you have a completely non-standard setup as the R packages for Debian / Ubuntu as use the external BLAS. Again, not an RInside issue.
I fixed the problem by adding the R install path lib ../R/lib: to the beginning of LD_LIBRARY_PATH after that all the examples compiled and run fine