I just want to successfully add it to my window, and it has been surprisingly difficult.
I've tried
#include "windef.h"
#include "winbase.h"
#include "initguid.h"
#include "ole2.h"
#include "olectl.h"
#include "shobjidl.h"
#include "shlguid.h"
#include "exdispid.h"
#include <objidl.h>
#include "OleIdl.h"
#include "Objbase.h"
#include <exdisp.h>
#include <exdispid.h>
...
IWebBrowser2* pBrowser2;
HRESULT hr = CoCreateInstance(CLSID_InternetExplorer, NULL,
CLSCTX_ALL, IID_IWebBrowser2, (void**)&pBrowser2);
Getting
error: 'CLSID_InternetExplorer' undeclared (first use in this function)
HRESULT hr = CoCreateInstance(CLSID_InternetExplorer,
I've also tried
CoCreateInstance(CLSID_WebBrowser, NULL, CLSCTX_LOCAL_SERVER,
IID_IWebBrowser2, (void**)&pBrowser2);
This one at least compiles, but nothing is added to the window:
hr = OleCreate(&CLSID_WebBrowser, &IID_IOleObject, 1/*OLERENDER_DRAW*/, 0,
&ClientSite, &Storage, (void**)&mpWebObject);
I tried all headers and libraries I could find on the net (as you can see).
Here are the libraries I link:
gcc -lmingw32 -mwindows -luser32 -lgdiplus -lole32 -luuid -loleaut32 -lcomctl32 -lcomdlg32 -ladvapi32 -loleaut32 -lshdocvw -lmf -lmfuuid
Thanks!
You could try MinGW-w64.
This is a fork of MinGW which , in addition to supporting both 32-bit and 64-bit builds, is under much more active development. In particular, having improved Windows API headers.
Apparently MinGW doesn't support IWebBrowser2. The code worked fine in Visual Studio.
Start by including these header files first:
#include <windows.h>
#include <objbase.h>
#include <ExDisp.h>
#include <ExDispid.h>
Then this:
IWebBrowser2* pBrowser2 = nullptr;
HRESULT hr;
hr = CoCreateInstance(__uuidof(WebBrowser), NULL, CLSCTX_INPROC, __uuidof(IWebBrowser2), (void**)pBrowser2);
The use of __uuidof macro takes resolves the linkage issues to externally defined guids.
Related
I am using MSYS2 mingw 64 when compiling code that needs the header random.h I am trying to make that code work on both Linux and windows with the least amount of changes
#include <sys/random.h>
#include <time.h>
#include <stdio.h>
#include <unistd.h>
int main()
{
srand(time(NULL));
return 0;
}
I ran this command pacman -S msys2-runtime-devel to download the random.h header file and it is located in sys official link
on linux, the file is included using #include <linux/random.c> but I don't know what to use on windows or if I have to do something completely different
When I comment the first line I get this warning
main.c:10:9: warning: implicit declaration of function 'srand' [-Wimplicit-function-declaration]
10 | srand(time(NULL));
| ^~~~~
As per the linked documentation,
srand is declared in #include <stdlib.h>.
rand is declared in #include <stdlib.h>.
Neither requires including random.h or linux/random.c.
Has anybody tried using the i2c_smbus_write_byte or any similar function on Raspberry Pi 4?
I can't get it compile it fails at the linking with not finding it.
I'm using it as described here: http://synfare.com/599N105E/hwdocs/rpi/rpii2c.html
All the headers recommended are there is and also the -li2c in the Makefile.
Can anybody tell what the problem can be? I have no clue at the moment.
Might be worth checking to see if libi2c-dev is present on your system.
sudo apt-get install libi2c-dev
may be all that you need.
The page you are linking to says:
With the Buster version, as of june 2019, the necessary details for
using i2c_smbus_write_byte_data() and siblings, require the following
include statements:
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
Using fgrep you can confirm that the function is declared in the /usr/include/i2c/smbus.h:
# cd /usr/include; fgrep -R i2c_smbus_write_byte *
i2c/smbus.h:extern __s32 i2c_smbus_write_byte(int file, __u8 value);
i2c/smbus.h:extern __s32 i2c_smbus_write_byte_data(int file, __u8 command, __u8 value);
So this should work:
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
int main(void) {
int i2c = open("/dev/i2c-1", O_RDWR);
i2c_smbus_write_byte(i2c, 1);
close(i2c);
return 0;
}
I tested that this example compiles successfully in the latest Raspbian Buster Lite:
gcc test.c -otest -li2c
If you are using g++ instead of gcc, then you should wrap the include directives with extern "C":
extern "C" {
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
}
Apple LLVM version 10.0.0 (clang-1000.10.44.4)
Target: x86_64-apple-darwin18.0.0
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#define _GNU_SOURCE
#define __USE_GNU 1
#include <fcntl.h>
int main()
{
int fd = open("./test.txt", O_WRONLY|O_DIRECT);
close(fd);
return 0;
}
I use clang -o out test.c and get the following result:
test.c:14:39: error: use of undeclared identifier 'O_DIRECT'
int fd = open("./test.txt", O_WRONLY|O_DIRECT);
How can I solve the problem?
Thank you.
With this snippet it is impossible to tell what you are trying to do, but in general do not use nonstandard stuff in applications intended to be portable.
The portable way to accomplish your task is probably fsync.
To sum up
For LINUX, the O_DIRECT flag has to be included. For Mac OSX, O_DIRECT is not available. Instead, fcntl(fd, F_NOCACHE, 1) looks to be the canonical solution where fd is the file descriptor of the file. For Windows, there is a flag called FILE_FLAG_NO_BUFFERING as the counterpart in Windows of O_DIRECT
Reference here
I am having a hard time finding this missing reference when running : gcc server.c -I /pwdmanlib/src -lssl -lcrypto -o server the include is my src files (headers needs etc..) and the rest is th required ssl libraries.
I am getting the following output from gcc:
In file included from server.h:49:0,
from server.c:39:
/pwdmanlib/src/util/constants.h:30:0: warning: "LINE_MAX" redefined
#define LINE_MAX 2048
^
In file included from /usr/include/limits.h:147:0,
from /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed/limits.h:168,
from /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed/syslimits.h:7,
from /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed/limits.h:34,
from /pwdmanlib/src/util/constants.h:26,
from server.h:49,
from server.c:39:
/usr/include/x86_64-linux-gnu/bits/posix2_lim.h:81:0: note: this is the location of the previous definition
#define LINE_MAX _POSIX2_LINE_MAX
^
In file included from server.c:39:0:
server.h: In function ‘start_server’:
server.h:126:34: warning: comparison between pointer and integer
if (p == NULL || listen_sock == NULL) {
^
In file included from server.c:39:0:
server.h: In function ‘routeClient’:
server.h:394:29: warning: passing argument 1 of ‘sendall’ makes pointer from integer without a cast [-Wint-conversion]
if (sendall(worker_sock, resp_data, fileLen) == -1) {
^
In file included from server.c:39:0:
server.h:70:5: note: expected ‘SSL * {aka struct ssl_st *}’ but argument is of type ‘int’
int sendall(SSL *ssl, char *buf, ssize_t *len);
^
/tmp/ccubinQD.o: In function `InitSSL':
server.c:(.text+0x1305): undefined reference to `OPENSSL_init_ssl'
server.c:(.text+0x1314): undefined reference to `OPENSSL_init_ssl'
server.c:(.text+0x1323): undefined reference to `OPENSSL_init_crypto'
/tmp/ccubinQD.o: In function `InitCTX':
server.c:(.text+0x1333): undefined reference to `TLS_server_method'
server.c:(.text+0x1350): undefined reference to `SSL_CTX_set_options'
collect2: error: ld returned 1 exit status
I found the OPENSSL_init_ssl function call in the ssl library and it is apparently getting included but can't be found by other references to it in the library?? The includes from my program are specified below:
ssl_funcs.h
#include <openssl/bio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/crypto.h>
server.h
#include <netdb.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <unistd.h>
#include "util/oop.h"
#include "util/stringops.h"
#include "util/constants.h"
#include "fawkes_proto.h"
#include "crypto/ssl_funcs.h"
server.c
#include <netdb.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <unistd.h>
#include "server.h"
#include "util/constants.h"
When linking in dynamic libraries with the -l option, these must occur last, after all other options:
gcc server.c -I /pwdmanlib/src -o server -lssl -lcrypto
Besides this, you should address the warnings in your code. These can potentially lead to undefined behavior.
To add to dbush's answer above I also needed to compile with an explicit target directory for the linking library like so: gcc server.c -I/pwdmanlib/src -o server -L/usr/local/lib -lssl -lcrypto
Moreover, I also implemented a solution for this in CMake (build system I use for my projects) and provided that below as well in case anyway else might find that useful. This is just the pertinent portion of it, if anyone wants the full src to the cmake I would be more than happy to provide it.
CMakeLists.txt
# Add libraries
include_directories(${LOCAL_LIBS_DIR})
include_directories("/usr/local/lib")
#link_directories("/usr/local/lib")
add_library(ssl SHARED IMPORTED) # or STATIC instead of SHARED
set_property(TARGET ssl PROPERTY IMPORTED_LOCATION "/usr/local/lib/libssl.so")
add_library(crypto SHARED IMPORTED) # or STATIC instead of SHARED
set_property(TARGET crypto PROPERTY IMPORTED_LOCATION "/usr/local/lib/libcrypto.so")
#include_directories("/opt/openssl-1.1.0e")
#find_package (my_library COMPONENTS REQUIRED component1 component2 OPTIONAL_COMPONENTS opt_component)
# Define build targets and link libraries
add_executable(main ${SOURCE_FILES})
target_include_directories(main PUBLIC /usr/include/openssl)
target_link_libraries(main
PRIVATE ${Boost_LIBRARIES}
PRIVATE ${PostgreSQL_LIBRARIES}
PRIVATE ${cJSON_ROOT_DIR}
# PRIVATE ${CryptoPP_ROOT_DIR}
# PRIVATE ${Kore_ROOT_DIR}
# PRIVATE ${POCO_LIBRARIES}
PRIVATE ssl
PRIVATE crypto
)
Given this code :
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/shm.h>
#include <semaphore.h>
#include <pthread.h>
#define BUF_SIZE 256
int main()
{
key_t key;
char *virtualaddr;
sem_t *get, *put;
int shmid;
const char* messageOne = "Hello world , I'm child number 1\n";
const char* messageTwo = "Hello world , I'm child number 2\n";
char buf[BUF_SIZE];
key = ftok("anyfile",'R');
shmid = shmget(key,1024,0644|IPC_CREAT);
...
...
shmctl (shmid, IPC_RMID, NULL);
exit(EXIT_SUCCESS);
}
I get from eclipse undefined reference to sem_open .
I've check with this post since this question is very similar to mine , but didn't understand exactly where is my mistake ,
Can you please explain where do I need to fix it / add another compilation command (if this is indeed the case) ?
Much appreciated
You need to include -lpthread when compiling. This is used by the linker, to link your binary against the library.
The other answers already cover how to do this on the command line.
To do this in Eclipse, you need to follow the directions here:
In the project properties, go to : C/C++ Build --> Settings. Then
"Tool Settings", select "Libraries" under "Linker". You can add all
your project libraries there (without the "-l"). Also in the lower
part, you can add custom path to search libraries
When linking, you have to add the flag -pthread or -lrt to the command line. It's right there in the manual page.
As it is written in the first answer in the question you linked, you nedd to compile it in this way:
gcc source.c -lpthread
-lrt or -pthread will do the same.