I'm trying to use InetPtonW:
if(InetPtonW(AF_INET, argv[1], &ThisSenderInfo.sin_addr)<=0) {
return 1;
}
However I get the following message when compiling:
warning: implicit declaration of function 'InetPtonW' [-Wimplicit-function-declaration]
undefined reference to `InetPtonW'
collect2.exe: error: ld returned 1 exit status
I've read the documentation located here and I've followed everything but still can't get it to work.
• I'm compiling with Ws2_32 library gcc test.c -o test -lws2_32 using MinGW
• I've included the needed header files #include <ws2tcpip.h> and #include <windows.h>
• I've tried using InetPton but it returns the same error
• Running on Windows 10
I recall running into this exact issue some many months ago. #alk's comment points to a question whose accepted answer feels very similar to what fixed it for me.
You should be able to #define a version macro (or two) before your #include lines to fix it.
While I feel strongly that the aforementioned answer is correct, I'll update this answer later today when I can verify.
Update!
The code I was referencing above doesn't have InetPtonW in it anymore but it had the necessary #defines in it. Here's a brief example that compiles on my machine (win10/mingw64/gcc 8.2.0):
Z:\Some\Directory>gcc test.c -o test -lmswsock -lws2_32
#define NTDDI_VERSION NTDDI_VISTA
#define WINVER _WIN32_WINNT_VISTA
#define _WIN32_WINNT _WIN32_WINNT_VISTA
#include <winsock2.h>
#include <Ws2tcpip.h>
#include <stdio.h>
/* This is "test.c", please pardon the lack of error checking. */
int main(void) {
BYTE ipbuf[4] = {0};
WSADATA wsa;
WSAStartup(MAKEWORD(2,2), &wsa);
printf("%d: ", InetPtonW(AF_INET, L"127.0.0.1", &ipbuf));
for(int i = 0; i < 4; ++i)
printf("%hhu.", ipbuf[i]);
WSACleanup();
}
Output should look like:
Z:\Some\Directory>gcc test.c -o test -lmswsock -lws2_32
Z:\Some\Directory>test
1: 127.0.0.1.
Z:\Some\Directory>
It's a linking error. which say that, included library path, the given function not found. please make sure your dll library path for InetPtonW or make sure that is available in your system or not.
Related
I have 2 c files (& their header files). I have included the function "put" in the corresponding header, but I still have the following errors, when I input "gcc -o main main.c" in the terminal.
main.c:(.text+0x389): undefined reference to `put' collect2: error: ld
returned 1 exit status
may I know the reason? How should I modify my code?
I tried to change the linking order in makefile but failed. Any advice is appreciated, thanks!
CMakeLists.txt
cmake_minimum_required(VERSION 3.19)
project(Demo)
set(CMAKE_CXX_STANDARD 14)
include_directories(.)
add_executable(Demo
main.c main.h KeyValueStore.c KeyValueStore.h )
main.c
#include "main.h"
...
int main() {
...
if (strcmp("PUT", tokens[0]) == 0) {
put(tokens[1], tokens[2]);
...
}
main.h
...
#include "KeyValueStore.h"
...
KeyValueStore.c
#include "KeyValueStore.h"
#define BUFSIZE 1024
typedef struct KeyValueStore {
char key[BUFSIZE];
char value[BUFSIZE];
} KV_Store;
KV_Store kvStore[BUFSIZE];
...
int put(char* key, char* value){
...
}
KeyValueStore.h
...
typedef struct KeyValueStore;
int put(char* key, char* value);
...
Check to see if you have any .o files in that folder and delete them if you do. It's possible the compiler failed at some point while compiling which left *.o files that aren't linked properly
EDIT: I misread the question because for some reason it came up as a c++17 question for me. I'm not sure if what I said still applies to C though I do know it works with C++. Sorry about that to everyone that read my answer before I edited it
Not 100% sure if this is why you are having the error, though you need to put all .c files in the compiler.
So you currently are trying to "gcc -o main main.c" where instead you want to do something more like "gcc -o main main.c keyValueStore.c".
If you do not give the compiler every .c file, it won't have all the definitions and you will get an error similar to what you have.
I also don't really think you need main.h, assuming there isn't any more code in there, it really isn't worth having a whole extra file and instead just putting the #include in main.c.
I'm trying to get the ADC running on beaglebone black. The OS is Debian GNU/Linux 7.7. I'm using C language. When I try to compile the following code:
#include <stdio.h>
#include <unistd.h>
#include "pruio_c_wrapper.h"
#include "pruio_pins.h"
int main(int argc, const char *argv[]) {
PruIo *io = pruio_new(0, 0x98, 0, 1);
if (io->Errr) {
printf("Initialisation failed (%s)\n", io->Errr);
return 1;
}
if(pruio_config(io, 0, 0x1FE, 0, 4, 0)){
printf("Config failed (%s)\n", io->Errr);
return 1;
}
int a = 0;
int i;
while(1){
printf("\r%12o %12o %12o %12o %4X %4X %4X %4X %4X %4X %4X %4X\n", io->Gpio[0].Stat, io->Gpio[1].Stat, io->Gpio[2].Stat, io->Gpio[3].Stat, io->Value[1], io->Value[2], io->Value[3], io->Value[4], io->Value[5], io->Value[6], io->Value[7], io->Value[8]);
fflush(STDIN_FILENO);
usleep(1000);
}
pruio_destroy(io);
return 0;
}
But I get the following error:
undefined reference to 'pruio_new'
undefined reference to 'pruio_config'
I installed everything like FreeBasic compiler and pruss driver kit for freebasic and BBB and libpruio. I also copied all the header files in the same directory as the .c file, including "pruio_c_wrapper.h", "pruio-pins.h", "pruio.h" and all the other files in the src directory of libpruio. But it doesn't work.
Could you please tell me what to do?
Thanks
libfb is the FreeBASIC run-time library. When you want to compile against the old libpruio-0.0.x versions, you'll need an old FreeBASIC installation from
www{dot}freebasic-portal.de/dlfiles/452/bbb_fbc-0.0.2.tar.xz
Which installs /usr/local/lib/freebasic/libfb.so.
See the libpruio-0.0.x C example codes for compiler command line arguments (ie. header section of io_input.c).
But I recommend to use the new version libpruio-0.2 from (the last post links to the documentation of this new version)
http://www.freebasic-portal.de/dlfiles/592/libpruio-0.2.tar.bz2
which doesn't have this pitfalls, gcc compiles without FB installation, and provides new features like pinmuxing, PWM, CAP. There're small bugs in this versions C header, which is now named pruio.h: a missing enum and a copy / paste bug regarding a function name. See this thread for details:
http://www.freebasic.net/forum/viewtopic.php?f=14&t=22501
BR
Ok, I downloaded it, the binaries are in libpruio-0.0.2/libpruio/src/c_wrapper and so are the include files, copy the headers and libpruio.so to the same directory where the test.c file resides, and then
For the includes, you need to to append libpruio's include directory to the compiler command using -I. then you can do
#include <pruio_c_wrapper.h>
#include <pruio_pins.h>
You need to append the library to the linker command, with
-L. -lpruio
your complete compilation command will be then
gcc -o test -I. -L. -lpruio test.c
I am working on this tutorial on building your own LISP (http://www.buildyourownlisp.com/chapter4_interactive_prompt) and for some reason when I try to compile I get this:
REPL.c:4:10: fatal error: 'editline/readline.h' file not found
#include <editline/history.h>
^
1 error generated.
I have installed the macOS developer tools, and brew is showing readline is installed and it doesn't know what to do when I try brew install editline.
This is my code:
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <editline/readline.h>
4 #include <editline/history.h>
5
6 int main(int argc, char** argv) {
7
8 /* version/exit info */
9 puts("Edward Version 0.0.1");
10 puts("Press Ctrl+c to Exit\n");
11
12 /* endless loop for main REPL */
13 while (1) {
14 /* output prompt and read line */
15 char* input = readline("lispy> ");
16
17 /* put input in history */
18 add_history(input);
19
20 /* Echo input back */
21 printf("No you're a %s\n", input);
22
23 /* free input */
24 free(input);
25 }
26 return 0;
27 }
It is obviously very basic, but I really want to get this project rolling so I'm hoping I can figure this out. This is what I'm using to compile:
cc -std=c99 -Wall REPL.c -ledit -o REPL
Include only
#include <editline/readline.h>
which should exist if the command line tools are installed. This file contains the
"readline wrapper" for libedit, including the history functions as well.
An include file <editline/history.h> does not exist on OS X.
I tested your code with that modification, and it compiled and ran without problems.
Using OSX Yosemite. I removed #include<editline/history.h>
and then used cc -std=c99 -Wall test.c -ledit -o test
Works fine now
I'm on El Capitan,
Remove #include <editline/history.h>,
and use cc -std=c99 -Wall test.c -ledit -o test works for me.
Add the flag -ledit before the output flad, it's a linking process, allows the compiler to directly embed calls to editline in your program. Or, you'll get the below error message,
Undefined symbols for architecture x86_64:
"_add_history", referenced from:
_main in prompt-086f90.o
"_readline", referenced from:
_main in prompt-086f90.o
ld: symbol(s) not found for architecture x86_64
I'm on Ubuntu 14.04.
try this:
sudo apt-get install libeditline-dev
and include like this:
#include <editline.h>
finally compile like this:
add -leditline in the flag
I hope this can help.
I'm on OSX Mavericks and removing the line worked for me:
#include <editline/history.h>
The solution for those following along on FreeBSD (might work on other Unices as well):
#include <stdio.h>
#include <stdlib.h>
#include <readline/readline.h>
#include <readline/history.h>
...
And run:
$ cc test.c -Wall -std=c99 -lreadline -o test
Without "-lreadline" in the compile step it is not linked in and you will get errors about undefined reference to "readline" function.
I started in on Build your own list and ran into the same problem.
None of the above answers worked for me. After a little research I found out that macOs doesn't have the gnu readline library that provides the readline functions, Different versions of MacOs provide emulation of readline using a library called editline. to begin...
man editline
#include <histedit.h>
Ok, editline gives you some structs for line input and history,
and functions to operate on them. First you have to instantiate these structs. The documentation for editline is not very helpful because it doesn't contain any examples. Apple makes the header file available so that helps a little. http://www.opensource.apple.com/source/libedit/libedit-13/src/histedit.h
I am new to this and it was still pretty confusing to me. there is some version of the source code to libedit available as a debian package. Fortunately someone wiser than I has already dug into it and implemented a command line using lbedit. His code is here: https://www.cs.utah.edu/~bigler/code/libedit.html.
I took Mr Bigler's code, and the code from Build your own list, and put them together to get this.
/* repl-macos.c
* Repl code example from builyourownlisp.com
* Modified by NB aug 2017
* Code example for editline from
* www.cs.utah.edu/~bigler/code/libedit.html
*/
#include <stdio.h>
#include <string.h>
#include <histedit.h>
char* prompt(EditLine *e){
return "lispy> ";
}
int main(int argc, char** argv){
EditLine *el; // Line editor state
History *herstory; // the rest is history
// Temp Variables
int count;
const char *usrin;
int keepreading = 1;
HistEvent ev;
// Initialize the editline state
el = el_init(argv[0], stdin, stdout, stderr);
el_set(el, EL_PROMPT, &prompt);
el_set(el, EL_EDITOR, "emacs");
// Initialize history
herstory = history_init();
if(!herstory){
fprintf(stderr, "Couldn't initialize history\n");
return 1;
}
//set history size
history(herstory, &ev, H_SETSIZE, 800);
// Set up the call back functions for history functionality
el_set(el, EL_HIST, history, herstory);
puts("Begin moLisp interpreter");
puts("Type 'exit' at prompt to exit");
while(keepreading){
usrin = el_gets(el, &count);
// add the command to the history, and echo it back to the user
if(count > 0){
history(herstory, &ev, H_ENTER, usrin);
if(strcmp(usrin, "exit\n"))
printf("No, You're a %s", usrin);
else{
puts("bye");
--keepreading;
}
}
}
// Clean up memory
// by freeing the memory pointed to within the structs that
// libedit has created.
history_end(herstory);
el_end(el);
return 0;
}
Notice: The instantiation of the structs that are used happens outside of
the while loop, and so do the functions that free the memory those structs are using. Because of this, I added the command to exit, otherwise I think there's a memory leak if the only way to exit the while loop is by interrupting the program. To compile:
gcc repl-macos.c -ledit -Wall -o repl-edit
-ledit is needed to link editline
If it has any relevance, I am using macOs 10.4.11
and here's my compiler, output of
gcc --version
powerpc-apple-darwin8-gcc-4.0.0 (GCC) 4.0.0 20041026 (Apple Computer, Inc. build 4061)
Now the only problem with this, and the book points this out, is that
c-code is supposed to be portable and this isn't. The next step would be to add preprocessor directives so that it uses readline on linux and editline on macos.
If you are on ubuntu add the editline library
sudo apt-get install libtedit-dev
On Debian Buster 10, I had to install the package with:
sudo apt install libeditline-dev
Instead of:
#include <editline/readline.h>
#include <editline/history.h>
I just included:
#include <editline.h>
ran the program with -leditline flag and worked perfectly.
I'm attempting to write a small program in C that will open and read from a Berkeley 4.2 hash DB on a FreeBSD 9.1 system for testing, but I can't get it to compile. This is the first time I've written anything in C and compiled from a command line so I'm probably missing one thing that'll get it working, I don't know.
After searching all over and looking at documentation and source code on github, this is what I've got so far:
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <db.h>
int main()
{
DB * mydb;
u_int32_t open_flags = DB_RDONLY;
int ret;
ret = db_create(&mydb, NULL, 0);
if (ret != 0) {
printf("Error creating DB structure!");
return 1;
}
ret = mydb->open(mydb, NULL, "bsddb-py", NULL, DB_HASH, open_flags, 0);
if (ret != 0) {
printf("Error opening DB file!");
return 2;
}
mydb->close(mydb, 0);
}
I compile with this:
cc -ldb-4.2 db_test.c
And get this:
db_test.c: In function 'main':
db_test.c:20: error: 'DB_RDONLY' undeclared (first use in this function)
db_test.c:20: error: (Each undeclared identifier is reported only once
db_test.c:20: error: for each function it appears in.)
db_test.c:29: error: 'DB' has no member named 'open'
db_test.c:35: error: too many arguments to function 'mydb->close'
Apparently the compiler is hung up on using Berkeley 1.85 (dbopen and such) and it won't budge?
It looks like #include <db.h> will provide an interface to Berkeley 1.85 because that's what's installed by default on FreeBSD. We have Berkeley 4.2 installed via ports, and to avoid conflicts, the header that interfaces with 4.2 is put elsewhere - I was referencing the right library but not the right header.
So, I changed the include to:
#include <db42/db.h>
...and compiled with...
cc -I/usr/local/include/ -L/usr/local/lib/ -ldb-4.2 db_test.c -o db_test
Running the above source with that modification produced no visible output, which means it worked!
As a newbie to it, BSD is weird.
DB_RDONLY is contained in some header file that you are not #including. That should take care of all the line 20 errors.
Line 29: a DB struct apparently doesn't have a member named open. Recheck the struct/maybe you forgot to include the file that that struct is declared in.
35: Seems like the function close doesn't take 2 arguments. Recheck this in the header file/make sure you included the header file.
I'm pulling out my hair trying to figure out why this isn't working on my Minix system.
When I try to compile my C program, I get the following error:
#make
link pm/pm
program.o: In function `do_function':
program.c:(.text+0x1e): undefined reference to `shmget'
program.c:(.text+0x36): undefined reference to `shmat'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1
Stop.
make: stopped in /usr/src/servers/pm
#
This is my code:
#include <sys/shm.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/stat.h>
/* Some other includes here */
typedef struct {
//struct elemLi *next;
//elem sem;
int ref_count;
} elemLi;
int do_function(void){
int segment_id; //Shared Memory ID
struct elemLi* sli; //Shared Memory Pointer
segment_id = shmget(IPC_PRIVATE, sizeof(elemLi),0660 | IPC_CREAT);
sli = (struct elemLi *)shmat(segment_id,NULL,0);
return -1;
}
As you can see, I've included the proper header files for these calls and it's still saying the references are undefined. I was able to successfully use this in another program, so I've completely run out of ideas as to why this isn't working in this instance.
Edit: This is within a system call. I assume that doesn't make a difference.
Thanks for the help everyone, it looks like it was a missing library in the linker. I added libc, using -lc, to the Makefile, and now it seems to be compiling fine.