I am trying to get MLPack to work in Eclipse, but have some problems with including a header file.
I manage to read a header file in Eclipse
#include <neighbor_search.hpp>
This header file calls itself
#include <mlpack/core.hpp>.
I included in Eclipse in the library path the path just upto mlpack/core.hpp, i.e.
/usr/include/MLPack/mlpack-1.0.8/src in the includes tab of paths and symbols.
I get the error message though:
/usr/include/MLPack/mlpack-1.0.8/src/mlpack/methods/neighbor_search/neighbor_search.hpp:26:27: fatal error: mlpack/core.hpp: No such file or directory
#include <mlpack/core.hpp>
How do set my path correctly so that <mlpack/core.hpp> will be found?
I also use MLPack (but not in Eclipse) and had this error.
To resolve this problem you have to specify to GCC where the files of mlpack are. The thing is when you include a header file with #include <file.h> , GCC looks in these directory :
/usr/local/include
libdir/gcc/target/version/include
/usr/target/include
/usr/include
So what I did is create a soft link in /usr/include/ to the mlpack directory :
cd /usr/include/
sudo ln -s /full/path/to/the/mlpack/folder/ mlpack
Like that the GCC will have access to mlpack directory.
You'll have to download and install at least these 2 libraries (if you don't have them) :
boost and armadillo.
Personally I also had to create a soft link for the libxml library :
cd /usr/include/
sudo ln -s /usr/libxml2/libxml/ libxml
I'm a bit in late to answer, but I hope it'll help further people !
http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.cdt.doc.user%2Freference%2Fcdt_u_prop_general_pns_libpath.htm
Project Properties -> C/C++ General category -> Paths and symbols -> Includes tab
Related
I have just installed hidapi in my Ubuntu 20.04 following the instructions, i.e. by doing
sudo apt install libhidapi-dev
I wrote my program in the file mwe.cpp which contains only this line:
#include <hidapi.h>
and now I want to compile it with
g++ -o mwe.o mwe.cpp
but I get
mwe.cpp:1:10: fatal error: hidapi.h: No such file or directory
How am I supposed to use this module? Sorry for such a basic question but cannot find out.
On Ubuntu based systems, the system package libhidapi-dev installs the include files to /usr/include/hidapi, so either include this (-I/usr/include/hidapi) in your command line or #include <hidapi/hidapi.h>
If that header is not within the standard search path for headers, then you can include it manually with the -I flag e.g.
g++ -I/usr/include/hidapi -o mwe.o mwe.cpp
To locate a file on ubuntu, you can run:
sudo updatedb
locate hidapi.h
> /usr/include/hidapi/hidapi.h
You can view the standard include search path with:
gcc -print-search-dirs
Alternatively, because /usr/include is on the standard search path, you can write your include as <hidapi/hidapi.h>.
How to #include <whatever.h> installed with apt in Ubuntu
If the package installs the header within a directory included in the default search path of your compiler - which is typical - then you can include the header using a relative path from the root of the search path where the header is installed. For example, if the file is in the path /usr/include/x/y.h, then you can include <x/y.h>.
If the package doesn't install the header within the default search path, then you must specify the search path for the compiler when you invoke it, and then include the header relative to the specified include directory. For example, if the file is in the path /opt/custom/x/y.h, then you can include <x/y.h> and specify /opt/custom as a search path for the compiler.
If you use GCC or compatible compiler, and the package supports it, then you can use a program called pkg-config to get the compiler options needed to use the library. Besides the header search path, this also takes care of linking with the library as well as any mandatory compiler options. Example:
pkg-config --libs --cflags libhidapi
I don't know, how do I find the location of hidapi.h?
There are several ways to find out the location of a file. A general tool is the program find. Example:
find / -name=hidapi.h
A more specific tool for learning the paths of files installed by an apt package is apt-file. Alternatively, you can look up the list of files in the https://packages.ubuntu.com/ website.
I'm trying to run this test code from the SDL website but I dont understand where to put the downloaded files and how to reference them using the g++ compiler. I've been trying to using the -I command but I dont quite understand that either. I keep getting the "fatal error: SDL.h: No such file or directory #include<SDL.h> "
Using windows and sublime text editor and g++ compiler
Directly from the g++ manual:
"-I dir
Add the directory dir to the list of directories to be searched for header files. Directories named by -I are searched before the standard system include directories. If the directory dir is a standard system include directory, the option is ignored to ensure that the default search order for system directories and the special treatment of system headers are not defeated . If dir begins with "=", then the "=" will be replaced by the sysroot prefix; see --sysroot and -isysroot."
As for your error, I would try #include <SDL2/SDL.h>. This could vary based on the version you are using. If that doesn't work I would just make sure you have the correct path when including in the compiler as a flag.
I'm a bit of a novice at C++ development. The goal is to download an correctly ready a new package so that Cygwin will understand the statement #include "pcap.h". The directions for the developer package for WinpCap were pretty straight forward:
Download the ZIP archive containing the developer's pack
Uncompress it to the desired folder
Developer Package Instructions Link
The part that I am having trouble with is the "desired folder" part. I found the path for where Cygwin is storing default libraries which for me is C:Cygwin64/usr/include . I placed the package in this directory but that didn't work. pcap.h is nested in the unzipped folders two or three directories in. I noticed that this is a little different when compared to the directories that were there by default. To test whether or not this was correct or not I simply did an #include "pcap.h" statement in a .cpp file that previously compiled with no issues. With the new included statement I got a
fatal error: pcap.h: No such file or directory
from Cygwin.
How should I go about solving this? The goal is to have this behave like any other directory one would want.
You could use this to find where gcc searches for the header files.
`gcc -print-prog-name=cc1plus` -v
The result of the command in a Cygwin console :
$ `gcc -print-prog-name=cc1plus` -v
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory "/usr/lib/gcc/i686-pc-cygwin/4.9.2/../../../../i686-pc-cygwin/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++
/usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/i686-pc-cygwin
/usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/backward
/usr/lib/gcc/i686-pc-cygwin/4.9.2/include
/usr/lib/gcc/i686-pc-cygwin/4.9.2/include-fixed
/usr/include
End of search list.
You could still maybe place your package's headers in one of them.
I have installed libusb by using the following command. I am not sure if it was right or not and the command was
sudo apt-get install libusb-dev
Once I have installed (and I am not sure if it has installed or not because I am a novice user of Ubuntu), I want to know how would I use the library, because I write some sample code which uses <libusb.h>, but when I compile that C++ file using
g++ test_libusb.cpp
that throws the following error,
test_libusb.cpp:2:20: fatal error: libusb.h: No such file or directory compilation terminated.
I am clueless what to do. I can't find any source on the Internet to get to the bottom of this...
I want to know two things here:
How do I add the libusb library in C/C++ so I can use <libusb.h>?
What would some sample code be? Only a few lines to see if libusb is working...
Try including it like so:
#include <libusb-1.0/libusb.h>
and then compile it like so:
g++ main.cpp -o main -lusb-1.0
Have a look at http://packages.debian.org/wheezy/i386/libusb-dev/filelist: The file you want to include is usb.h. Also, you'll have to tell the compiler where it can find the compiled library functions: Add -lusb to the compiler command line to make it load libusb.so.
Actually at least in Debian 7.4 (wheezy), and probably in Ubuntu also, there are two distinct libusb packages: libusb-dev (0.1.12-20+nmu1) and libusb-1.0-0-dev (1.0.11-1). Confusingly, they can both be installed concurrently and provide header files in different locations:
$ dpkg -L libusb-dev|grep /usr/include
/usr/include
/usr/include/usb.h
$ dpkg -L libusb-1.0-0-dev|grep /usr/include
/usr/include
/usr/include/libusb-1.0
/usr/include/libusb-1.0/libusb.h
Try #include <usb.h>. The "lib" is part of the Linux naming convention, i.e. library "foo" has header foo.h and is called libfoo-dev in the Debian package structure, and linked as -lfoo, and the compiled library files are called libfoo.a and libfoo.so.
I have compiled this library successfully. It generates a libcds2.la file that I am trying to link into my own project. I have all files (including the .h file) in the same directory as my project file. When I try to link and use the functions of said library, using:
g++ -o test -I/opt/include/ -L/opt/lib/ -lcds2 libcdsNoptrs.cpp util.cpp
comes back with
./test: error while loading shared libraries: libcds2.so.2:
cannot open shared object file: No such file or directory
whatever that is. But the point is that most of the time it just doesn't recognize the library. I assume I'm doing something wrong with the file paths, but can't figure it out. My test file is a C++ file including #include "libcds2/array.h" and everything is installed in opt/lib, opt/include, ugly, I know, but that's what the Makefile generated.
Any pointers?
The libtool .la is a 'meta data' file. After building the cds2 library, it's expected that libtool will also be used in 'link' mode to build any of the package's tests, etc.
Typically, the in the directory you find the .la file, you will find the .a and .so under the .libs subdirectory. The .libs/libcds2.a file will be found there, provided configure was given the --enable-static option (or it is enabled by default). But, my understanding is that you've installed the package in /opt :
g++ -I/opt/include/ libcdsNoptrs.cpp util.cpp -o test /opt/lib/libcds2.a
Otherwise, if libcds2 isn't installed, just supply a path to: .../libcds2/lib/.libs/libcds2.a
Unless you want to use libtool in --link mode with -static to handle everything. But learning the advantages of libtool is usually an exercise for a rainy day:)