eclipse pointing to wrong header file - c

I am writing some C code in eclipse. I have some of my own header files and I put them under project properties -> GCC C Compiler -> Includes -> Include paths(-l). One of the inclded file is socket.h. When I try to compile my project compiler still points to default library (usr/includes/bits/socket.h and /usr/includes/sys/socket.h) But I have my own socket.h file which I have included under include paths(-l).
My question is, How can I restrict my compiler to point my socket.h rather than its own socket.h ? One restriction is that I cant change socket.h file name.

An easy and fast way to solve this, is to put your socket.h in a subfolder and make your include look like this:
#include "mysubfolder/socket.h"
Add the subfolders parent folder to your include paths and your done.

Related

How to include a folder of libraries in C?

I'm trying to include a folder that contains a combination of around 60 .h and .hpp files. This folder contains libraries for programming robots with a Wallaby (a mini-computer-like device) for Botball competition. include is located in the same place as main.c (inside code). Up until now, this is what my header for including libraries looks like:
#include "../code/include/accel.h"
Just like accel.h, I have 60 other .h and .hpp files inside include. So, coming to my question, do I need to type out all the 60 header lines? or is there a way to include the include folder.
I'm using Clion for this project, if I can't include the folder itself, does anyone know of a shortcut in Clion to include all the files in include.
I was also thinking of using some sort of placeholder for the folder name and only specify the file type. So, for example: #include "../code/include/(generic placeholder name).h". I have no clue if something like this exists.
I would also request you to keep in mind that I'm a beginner to programming, so please keep your answers simple.
This is just for some extra info:
The Wallaby is a mini computer to which you would connect your sensors, motors, servos and cameras in order to control a robot for the Botball competition. Usually, one can connect to the Wallaby either via Wifi Direct or a cable and write programs on it directly through an online interface (not entirely sure of the word for it, but you just type in an IP address in your browser and it brings up an interface where you can make projects and code). All the code written in that interface saves directly onto the Wallaby. Here the default include statement is #include <kipr/botball.h>, so I'm assuming that botball.h (which is located on the Wallaby's storage) has all those 60 libraries consolidated in it. I got the include folder that I'm using from GitHub. This link was provided to me by one of the Botball organisers. So the main point in me trying to download the library is so that I can write and successfully compile code even when I'm not connected to the Wallaby. Hope this provides some relevant context.
Thank you for your answers!
What I'd do is
Create (maybe with scripting tools or a specific program) a "all.h" file which includes all the other header files
#ifndef ALL_INCLUDED
#define ALL_INCLUDED
#include "accel.h"
#include "bccel.h"
//...
#include "zccel.h"
#endif
Include "all.h" in your main file
#include "../code/include/all.h"
You can create "all.h" automatically every time you build your code.
CLion is an IDE for Clang and GCC. These compilers are instructed to search paths for include files by specifying -I<path> command line arguments. Any number may be specified, and they are searched in the order given, and the first match found is the file that gets included.
I am not familiar with CLion specifically but no doubt it has a dialog somewhere where you can set header file search paths.
Edit: It seems that CLion may not make this so straightforward. I understand that you have to add then via CMake: https://cmake.org/cmake/help/v3.0/command/include_directories.html#command:include_directories, but after that, the IDE will not recognise the header in the editor and will warn you of unrecognised files and will not provide code comprehension features. I believe it will build nonetheless.

How to include custom .h files in /usr/include

I have some custom .h files placed under /usr/include, but in a directory (/usr/include/itsmag1c), and I'm trying to include them in my C file. I'm guessing that because I use
#include "filename.h";
for files in the same directory, and I would use angle brackets for including a file like math.h or stdio.h. Am I right in guessing that I would use the angle brackets for including my custom header files? If so, my program wont compile, I get the error that the included files cannot be found. Can someone please point to me how I would include these files, or would it be best to have them in the same directory as my program?
Two choices:
Use #include <itsmagic1c/filename.h>
Use #include <filename.h> as before but add a -I switch.
Boost etc use method 1. (which works well provided you have Boost installed in system locations as you would on a reasonably standard Linux box with reasonable package management).
Method 2. is fine too, but more work on the build system, Makefiles, etc.
Usually, you would put your own headers in the same directory or in a subdirectory. Same-dir includes work with "". For bracket includes, if you use gcc, you can pass additional include directories with
-Irelativedir
or
-I/usr/local/yourpath.

How to link a non-standard header file into a C compiler

I'm trying to use a non-standard header file (http://ndevilla.free.fr/gnuplot). Its used in lots of codes in various different places on my computer. Currently I have to put the header file and the object file in every folder which its needed with the preprocessor directive:
#include "gnuplot_i.h"
In the file. Is there a way by which I can put the header file in one place so I can reference it like other standard header file. Cheers.
Compile with -I<directory>
E.g.
compile with -I/usr/local/gnuplot/inc.
Also it might be worth your reading up on include paths and the difference between:
#include <include_file.h>
and
#include "include_file.h"
Linking in an object file needs to be done explicitly the same way as a C file, which means (I believe) that you need a full path. However if you archive it into a proper library then you can use -l<library name> and -L<library path> instead. E.g.
gcc -I/usr/local/gnuplot/inc -L/usr/local/gnuplot/lib -lgnuplot -o my_prog my_prog.c
Most compilers have a flag -I that lets you add a directory of your choosing to the search path for include files.

Copy C files to include

I have a set of C files that I would like to use. Can I just copy them to my include directory, or do I have to compile them. I would think they would be compiled in the final binary.
You need to compile those C files if you want to use them.
To make use of what's in those C files, you'll nead a header file that declares what's inside them.
Those header files is what you'd put in your include folder, and you'll compile the C files together with your other C files. (Or you could make a library out of those C files)
Yes, they need to be compiled so that they are available at the linking step. C is not an interpreted language, so having the sources present in an include directory would do nothing for execution.
You can keep the source files at the same location. The include files will be in the include directory. You can use the compilation option -I./<include-file-directory> to specify from where to fetch the include files.
The final binary will be compiled version of all your source files which you give to the compiler. You have to explicitly specify every file to be compiled along the with final executable name.
In case you dont do so a default executable is created with the name a.out(i am assuming the platform to be linux and compiler to be gcc) in the directory where you compile.
Check the link for more details on compilation using Makefile.

How to install new units (i mean includes ex: stdio.h) for my C

How to install new units (i mean includes ex: stdio.h) for my C, and how to download more?
put the header file on the same folder as your main source file,
ex:
/folder /-->main.c
-->function.h
-->function.c
then on main.c include it by writing :
#include "function.h"
the quotes are used to include a header file that's on the same folder as your c source file
u can also write your own and include them like above.
You're looking for libraries. The headers (normally) just contain information to tell the compiler about the content of the library. There are quite a few C libraries to be found, covering all sorts of different topics. Of course, SourceForge isn't the only place to look -- Github and Google code would be a couple more obvious ones.

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