In my project, I include pfring.h, but compile error: some functions in net/if.h and linux/if.h are redefinition. I found that the pfring.h include linux/if.h
So, I test a program, my test code:
#include <linux/if.h>
#include <net/if.h>
int main(void) {
return 0;
}
It expected compile error.
So, what's wrong with linux/if.h and net/if.h ?
Can not I include them at once?
error message:
In file included from test.c:1:0:
/usr/include/linux/if.h:178:19: error: field 'ifru_addr' has incomplete type
/usr/include/linux/if.h:179:19: error: field 'ifru_dstaddr' has incomplete type
/usr/include/linux/if.h:180:19: error: field 'ifru_broadaddr' has incomplete type
/usr/include/linux/if.h:181:19: error: field 'ifru_netmask' has incomplete type
/usr/include/linux/if.h:182:20: error: field 'ifru_hwaddr' has incomplete type
In file included from test.c:2:0:
/usr/include/net/if.h:45:5: error: expected identifier before numeric constant
/usr/include/net/if.h:112:8: error: redefinition of 'struct ifmap'
/usr/include/linux/if.h:136:8: note: originally defined here
/usr/include/net/if.h:127:8: error: redefinition of 'struct ifreq'
/usr/include/linux/if.h:170:8: note: originally defined here
/usr/include/net/if.h:177:8: error: redefinition of 'struct ifconf'
/usr/include/linux/if.h:219:8: note: originally defined here
For me (on Ubuntu 12.04 x64) the following include solved the problem:
#include <sys/socket.h> // <-- This one
#include <linux/if.h>
#include <linux/if_tun.h>
This problem has been resolved, add the compile flag -DHAVE_PCAP is fix. ;-)
At first let us talk about the source: The header files are from different Packages as you can see asking dpkg.
$ dpkg -S /usr/include/linux/if.h
linux-libc-dev:i386: /usr/include/linux/if.h
$ dpkg -S /usr/include/net/if.h
libc6-dev:i386: /usr/include/net/if.h
linux-libc-dev is part of linux kernel packages while libc6-dev is part of the libc6 (Standard C library in version 6).
It seams like they are interchangeable so you should only use one (not 100% sure about this). If you pick linux/if.h, you may depend on Kernel versions with your compiled binary.
All new Library versions I have in mind stick with net/if.h instead of the linux one - so you should do the same.
If you are using one of the interface state flags (eg: IFF_UP, etc.), you need one more header than mentioned in other posts.
#include <sys/types.h> // <==
#include <sys/socket.h>
#include <linux/if.h>
Related
A complete newbie here. I am learning to read the codes on suckless.org. They are written in C, and are most quite short, so I think it's a good start.
The problem is I know too little to start with. Wandering around on the site, I found that the suckless community has their own coreutils, which are also very short. echo.c on this page is one of the shortests. I include its header here:
/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <string.h>
#include "util.h"
I'd like to compile it and see how this version of echo works, and come back to understand the code. The goal is to repeat this process until I'm comfortable enough to read the source codes of their their larger programs like sent, dmenu, dwm.
In the code, the header #include "util.h" suggests me to put util.h, which is another file in the link above, together with echo.c. I also include arg.h and compat.h because the header of util.h says
#include <sys/types.h>
#include <regex.h>
#include <stddef.h>
#include <stdio.h>
#include "arg.h"
#include "compat.h"
I further checked arg.h and compat.h. Neither of them includes customized header files, so I think I'm good to go. Now the folder tree looks like
$ tree
.
├── arg.h
├── compat.h
├── echo.c
└── util.h
and I run $ gcc echo.c -o echo.o. However, I got an error
/usr/bin/ld: /tmp/cc2VjXNO.o: in function `main':
echo.c:(.text+0x20): undefined reference to `argv0'
/usr/bin/ld: echo.c:(.text+0x27): undefined reference to `argv0'
/usr/bin/ld: echo.c:(.text+0x8d): undefined reference to `putword'
/usr/bin/ld: echo.c:(.text+0xc8): undefined reference to `fshut'
collect2: error: ld returned 1 exit status
Apparently, these undefined arguments are in those header files. Searching around on the net, I further tried
$ gcc -c . echo.c -o echo.o
gcc: warning: .: linker input file unused because linking not done
It spits a warning, but anyway an echo.o is delivered. I chmod it to executable, and run it by $ ./echo.o, but my shell complains
zsh: exec format error: ./echo.o
I spent another hour trying to solve this.. by try and error, but in vain. Would you please point out what's going on? And what should I do?
(Any other suggestions will also be very appreciated.)
You try to compile a program with library that you don't have. The header you're using needs a dynamic or static library (either .a or .o on linux). That's why you get linker input file unused because linking not done.
zsh: exec format error: ./echo.o if you use .o extension with -o argument, you're either making or linking a .o object file (static lib). With gcc -c . echo.c -o echo.o, you're creating a static library (called object) that you won't be able to execute.
By the way, I'd stay away for now from this kind of code, it's very not friendly user for a learner.
I am looking for a way to use cufft.h a CUDA toolkit which perform GPU parallelization of fast fourier transform.
First of all, I downloaded cuda library and cufft through synaptic.
Then I used the sample program from the cufft documentation from NVidia.
my cuda library is located at /usr/local/cuda-9.0 on my laptop.
I added those include :
1 #include <iostream>
2 #include <cstdio>
3 #include "/usr/local/cuda-9.0/include/cuda.h"
4 #include "/usr/local/cuda-9.0/include/cuda_runtime_api.h"
5 #include "/usr/local/cuda-9.0/include/cufft.h"
I compile like this :
g++ -Wall main.cpp -o main
and get undefine references error for each cuda-like functions (cudaMalloc,cudaGetLastError, etc...)
I am pretty young about library implementation and I don't understand what should I do to include properly this cuda-cufft library...
The nvidia documentation talk about filename.cu but I don't know what this is about...
Thank you for your time :)
n.b : I added cuda.h and cuda_runtime_api.h after reading a forum (I forgot which it was). Apparently, only cuda_runtime_api.h is necessary (I tried without cuda.h and get the same errors).
Here is a complete sample code (that doesn't do anything useful) and a sample g++ compile command that will properly compile and link the code:
$ cat t1338.cpp
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <cuda_runtime.h>
#include <cufft.h>
int main() {
size_t work_size;
int fft_sz = 32; // Size of each FFT
int num_ffts = 1; // How many FFTs to do
cufftComplex *in_buf_h, *in_buf_d, *out_buf_d;
// Allocate buffers on host and device
in_buf_h = new cufftComplex[fft_sz*num_ffts];
cudaMalloc(&in_buf_d, fft_sz*num_ffts*sizeof(cufftComplex));
cudaMalloc(&out_buf_d, fft_sz*num_ffts*sizeof(cufftComplex));
cudaMemset(out_buf_d, 0, fft_sz*num_ffts*sizeof(cufftComplex));
// Fill input buffer with zeros and copy to device
memset(in_buf_h, 0, fft_sz*num_ffts*sizeof(cufftComplex));
cudaMemcpy(in_buf_d, in_buf_h, fft_sz*num_ffts*sizeof(cufftComplex), cudaMemcpyHostToDevice);
// Plan num_ffts of size fft_sz
cufftHandle plan;
cufftCreate(&plan);
cufftMakePlan1d(plan, fft_sz, CUFFT_C2C, num_ffts, &work_size);
// Execute the plan. We don't actually care about values.
cufftExecC2C(plan, in_buf_d, out_buf_d, CUFFT_FORWARD);
// Sync the device to flush the output
cudaDeviceSynchronize();
return 0;
}
$ g++ t1338.cpp -I/usr/local/cuda/include -L/usr/local/cuda/lib64 -lcudart -lcufft
$
Your include statements are probably OK as-is, but I have used a format that says "search on the standard path for this file" and then I identify an addition to the standard path with
-I/usr/local/cuda/include
However your compile command is definitely missing the necessary link apparatus. You need to specify where to find the libraries (the path) with -L and then indicate the specific libraries to include, which are both the CUDA runtime library (-lcudart) and also the CUFFT library (-lcufft):
-L/usr/local/cuda/lib64 -lcudart -lcufft
The CUDA toolkit normally gets installed with sample codes which will have sample Makefiles you can inspect, or just compile those projects to see typical compilation command usage.
As I mentioned, this source code is incomplete. It doesn't do anything useful. It is just to demonstrate proper compilation behavior. In particular, I've omitted proper error checking, which I recommend you include in your actual codes.
Depending on whether your install created a symbolic link or not, you may need to change the above paths to:
-I/usr/local/cuda-9.0/include
and
-L/usr/local/cuda-9.0/lib64 -lcudart -lcufft
I'm programming c++ in Borland c++ 5.02. I'm trying to run this code:
#include <stdio.h>
#include <pthread.h>
#define NUM 5
main()
{
pthread_t t1, t2; /* two threads */
void *print_msg(void *);
pthread_create(&t1, NULL, print_msg, (void *)"hello");
pthread_create(&t2, NULL, print_msg, (void *)"world\n");
pthread_join(t1, NULL);
pthread_join(t2, NULL);
}
But I get this error:
Info :Compiling C:\BC5\BIN\noname00.cpp
Error: noname00.cpp(2,2):Unable to open include file 'PTHREAD.H'
Error: noname00.cpp(8,15):Undefined symbol 'pthread_t'
Error: noname00.cpp(8,15):Statement missing ;
Error: noname00.cpp(12,18):Call to undefined function 'pthread_create'
I highlighted the main error which is caused by 'PTHREAD.H'. I checked the include folder for this file. It doesn't exist. How can I fix this problem?
Borland's C++ toolchain doesn't include a pthreads library, nor does the Windows SDK. You'll either need to use native Win32 thread APIs or get a 3rd party pthreads implementation for Windows.
Some options include:
winpthreads.h: http://locklessinc.com/articles/pthreads_on_windows/
pthreads-win32: https://www.sourceware.org/pthreads-win32/
I have no idea how well those things work with Borland C++ 5.x.
Another alternative is to use a toolchain that includes a pthreads implementation, such as TDM's MinGW toolchain:
http://tdm-gcc.tdragon.net/
your problem is #include <pthread.h>
you need either copy all the pthread related files (.h,.c,.cpp,.hpp,.lib,.obj)
into compiler include folder
or add include path to it in your project/compiler settings
or copy it locally to your project and change #include <pthread.h> to #include "pthread.h"
So compiler did not find the pthread.h header
so no datatype from it is known from compiler side (like pthread_t)
therefore the rest of the errors...
I'm using RHEL5 kernel 2.6.33 and running GCC v4.1.2.
During my program compilation, I get the warning "implicit declaration of function CPU_ALLOC" and the error "undefined reference to 'CPU_ALLOC'. I get the same warnings and errors for CPU_ZERO_S, CPU_SET_S, CPU_FREE, numa_bitmask_alloc, numa_bitmask_setbit and numa_bitmask_free.
I understand that CPU_ALLOC should be found in sched.h, but I've searched several sched.h (/usr/include/sched.h, /usr/include/bits/sched.h, /usr/include/linux/sched.h, /usr/src/kernels/linux-2.6.33.1/include/linux/sched.h), and cannot find CPU_ALLOC.
I have tried both #include <sched.h> and #include "/usr/include/sched.h", but I still have the errors.
I found declarations of CPU_ALLOC and the other functions on this website. Is this a file that I should have on my system?
How do I resolve this problem with the CPU_* and numa_bitmask_* functions?
Thank you.
Regards,
Rayne
You need to include the following in your header file containing CPU_ALLOC.
#define _GNU_SOURCE
#include <sched.h>
I am using Visual Studio 10 to program in C++
The 1st part of my program is
//Includes
//#include <LEDA\numbers> //fatal error C1083: Cannot open include file: 'LEDA\numbers': No such file or directory
#include <LEDA/numbers/real.h>
//Why do I get a linker error here
//All.obj : error LNK2001: unresolved external symbol "class leda::memory_manager leda::std_memory_mgr" (?std_memory_mgr#leda##3Vmemory_manager#1#A)
#include <LEDA\numbers\integer.h> //Here I used the system to write most of it for me
#include <LEDA/numbers/integer.h> //Include LEDA. So 2 things
//1. including the same file twice does not matter
//2. forward slashes and backward slashes are the same
//I tried to use a wild card and said #include <LEDA/numbers/*>
//But that did not work
#include <LEDA/numbers/rational.h>
#include <LEDA/core/string.h>
#include <LEDA/core/array.h>
#include <LEDA/numbers/bigfloat.h>
//The sqrt does not work
#include <iostream> //include ordinary C++
#include <math.h>
and I have a LINKER error
I have tried specifying which libraries to use by specifying the LIB User Environment symbol
I have tried specifying which libraries to use by specifying the
Include Directories and
Library Directories
in the properties of my Project
I have made a mistake somewhere, BUT where is it
There are several mistakes in this program:
LEDA\numbers is apparently a directory, not an include file. So you shouldn't try to include it.
(conceptual) #include statements don't help in resolving linker errors at all. Instead, you need to specify the libraries you want to link with to the linker; libraries are files that end in .lib. Go to the project settings, and add the libraries containing the missing symbols.
#include <abcd.h> // looks for the include abcd.h in the INCLUDES path.
#include "abcd.h" // looks for the include abcd.h in the current path and then INCLUDES path.
From your description it looks like your LEDA lib in under your current directory. Try using "" instead of <> and see if it fixes your errors.