I have written a few programs and while trying to compile them using g++,as thus,
$ g++ minIni.c device_datum.cpp fanuc_axis.cpp fanuc_path.cpp service.cpp condition.cpp cutting_tool.cpp string_buffer.cpp logger.cpp client.cpp server.cpp adapter.cpp fanuc_adapter.cpp FanucAdapter.cpp -L/usr/local/lib/ -lfwlib32 -lpthread -o adapter
I keep getting the following error:
/usr/bin/ld: cannot find -lfwlib32
collect2: error: ld returned 1 exit status
fwlib32.h is the library I am trying to include. The shared object file libfwlib32.so is present in /usr/local/lib as well as /usr/lib. But I am unable link to it. I have tried all the solutions offered by similar questions including
$ export LIBRARY_PATH=/usr/local/lib/
$ export LD_LIBRARY_PATH=/usr/local/lib
I have done the above for /usr/lib as well, but still the same error.
I have tried using the -L option in the command line but I still get the error.
I even created a new folder called lib, pasted libfwlib32.so.1.0.1 into it and ran
$ ln -s ~/lib/libfwlib32.so.1.0.1 ~/lib/libfwlib32.so
on the console to create a new .so file and gave ~/lib as argument to -L option on the command line. It made no difference. I am at the point of tearing my hair out so any help will be appreciated.
Thanks alot!
You should put -l option in the very last as:
$ g++ minIni.c device_datum.cpp fanuc_axis.cpp fanuc_path.cpp service.cpp condition.cpp cutting_tool.cpp string_buffer.cpp logger.cpp client.cpp server.cpp adapter.cpp fanuc_adapter.cpp FanucAdapter.cpp -L/usr/local/lib/ -o adapter -lfwlib32 -lpthread
Note: Please make sure that all the header and source file are in the same folder.
Note that specifying -L~/lib won't work as the ~ will not be expanded by the shell. Also you can't add a space between -L and ~/lib. Instead you must specify it as a relative or absolute path.
Have you checked that the libfwlib32.so symlink exists in /usr/local/lib (or /usr/lib) in addition to the libfwlib32.so.1.0.1 file?
Another possibility is that the library is the wrong architecture (ie. 32-bit while your system is 64-bit), but then ld should print a message about skipping incompatible library. You can check the architecture of the library by running 'file libfwlib32.so.1.0.1'.
The error message suggests that -lfwlib32 is being interpreted as a filename not as a -l parameter. Put all the parameters before the files to be compiled
g++ -m32 -L/usr/local/lib/ -lfwlib32 -lpthread -o adapter minIni.c device_datum.cpp fanuc_axis.cpp fanuc_path.cpp service.cpp condition.cpp cutting_tool.cpp string_buffer.cpp logger.cpp client.cpp server.cpp adapter.cpp fanuc_adapter.cpp FanucAdapter.cpp
As has been pointed out by #Erik Johannessen, libfwlib32.so is a 32bit library, so you need to add -m32 to build a 32bit executable.
Related
I'd like to learn how to write PNG images pixel-by-pixel using both RGB and HSV color models with C++. I read that this should be fairly easy using PNGwriter (https://github.com/pngwriter/pngwriter), but I've spent many hours struggling with installing it (on Ubuntu) and compiling my code with it. Any help would be much appreciated.
Disclaimer: I have a weird background in the sense that I have many years of experience in using Unix-like operating systems, doing stuff in the terminal, and writing code, but I know little/nothing about installing software from the source code or compiling programs manually or with makefiles from multiple source code files.
The installation instructions on GitHub advise to do one of the following:
Spack:
spack install pngwriter
spack load pngwriter
From Source:
First install the dependencies zlib, libpng, and (optional for text support) freetype. PNGwriter >can then be installed using CMake:
git clone https://github.com/pngwriter/pngwriter.git
mkdir -p pngwriter-build
cd pngwriter-build
# for own install prefix append: -DCMAKE_INSTALL_PREFIX=$HOME/somepath
cmake ../pngwriter
make -j
# optional
make test
# sudo is only required for system paths
sudo make install
I managed to install Spack and then PNGwriter, but couldn't compile the simplest program with it and wasn't able to figure out why. I then installed PNGwriter manually, but still couldn't compile anything with it. This was many hours of struggling ago so I, unfortunately, don't remember what kind of errors or problems I was encountering at this point.
The instructions on GitHub say the following about linking:
First set the following environment hint if PNGwriter was not installed in a system path:
# optional: only needed if installed outside of system paths
export CMAKE_PREFIX_PATH=$HOME/somepath:$CMAKE_PREFIX_PATH
Use the following lines in your projects CMakeLists.txt:
find_package(PNGwriter 0.7.0)
if(PNGwriter_FOUND)
target_link_libraries(YourTarget PRIVATE PNGwriter::PNGwriter)
endif(PNGwriter_FOUND)
Questions: How do I know if PNGwriter was or wasn't installed in a system path? I have libPNGwriter.a in /usr/local/lib and pngwriter.h in /usr/local/include --- does this mean that it was installed in a system path? When installing I simply tried to follow the instructions above. Do I just type the environment hint to the terminal or add it to some file? If the former then does it need to be given every time I open a new terminal session? Is "somepath" /usr/local/lib, /usr/local/include or something else?
Questions: Does the second part regarding "CMakeLists.txt" depend on whether PNGwriter was installed in a system path? What is "CMakeLists.txt"? I assume it's some file one's IDE creates, but my NetBeans projects don't seem to contain such files. What if I have a single source file and compile it manually in the terminal?
Now, let's say I'd like to compile the PNGwriter quickstart example:
#include <pngwriter.h>
int main()
{
int i;
int y;
pngwriter png(300, 300, 0, "test.png");
for(i = 1; i ≤ 300; i++)
{
y = 150 + 100*sin((double)i*9/300.0);
png.plot(i, y, 0.0, 0.0, 1.0);
}
png.close();
return 0;
}
The PNGwriter manual instructs to compile as
g++ myprogram.cc -o my_program `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lpng -lpngwriter -lz -lfreetype
but I get errors
$ g++ example.cpp -o example `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lpng -lpngwriter -lz -lfreetype
Package freetype2 was not found in the pkg-config search path.
Perhaps you should add the directory containing `freetype2.pc'
to the PKG_CONFIG_PATH environment variable
Package 'freetype2', required by 'virtual:world', not found
Package freetype2 was not found in the pkg-config search path.
Perhaps you should add the directory containing `freetype2.pc'
to the PKG_CONFIG_PATH environment variable
Package 'freetype2', required by 'virtual:world', not found
Package freetype2 was not found in the pkg-config search path.
Perhaps you should add the directory containing `freetype2.pc'
to the PKG_CONFIG_PATH environment variable
Package 'freetype2', required by 'virtual:world', not found
Package freetype2 was not found in the pkg-config search path.
Perhaps you should add the directory containing `freetype2.pc'
to the PKG_CONFIG_PATH environment variable
Package 'freetype2', required by 'virtual:world', not found
sed: -e expression #1, char 0: no previous regular expression
sed: -e expression #1, char 0: no previous regular expression
In file included from example.cpp:1:0:
/usr/local/include/pngwriter.h:66:22: fatal error: ft2build.h: No such file or directory
compilation terminated.
The answer to this Stack Overflow question (Trying to install pygame on ubuntu which gives error) suggests to install libfreetype6-dev, but I apparently have the latest version already whereby the errors remain unchanged. If I instead actually add the directory containing freetype2.pc (I found it by going to / and using find -name "freetype2.pc") to the environment variable (added export PKG_CONFIG_PATH="/usr/lib/x86_64-linux-gnu/pkgconfig/:$PKG_CONFIG_PATH to ~/.bashrc and did source ~/.bashrc) then I get new errors
$ g++ example.cpp -o example `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lpng -lpngwriter -lz -lfreetype
/usr/bin/ld: cannot find -lpngwriter
collect2: error: ld returned 1 exit status
Here I figured out that I needed to replace -lpngwriter with -lPNGwriter (i.e., the manual is erroneous). Then I get:
$ g++ example.cpp -o example `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lpng -lPNGwriter -lz -lfreetype
/usr/bin/ld: /usr/local/lib/libPNGwriter.a(pngwriter.cc.o): undefined reference to symbol 'png_set_sig_bytes##PNG12_0'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/libpng.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
This is where I'm currently stuck. I can't seem to find a solution by googling (at least one that I'd understand).
Question: How do I get this working? How do I get it working in NetBeans? Do I get these problems because I effed up the linking step above?
Edit1: As per john's comment, I tried swapping -lpng and -lPNGwriter and I again get new errors:
$ g++ example.cpp -o example `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lPNGwriter -lpng -lz -lfreetype
/usr/local/lib/libPNGwriter.a(pngwriter.cc.o): In function `pngwriter::close()':
pngwriter.cc:(.text+0x41c2): undefined reference to `png_convert_to_rfc1123_buffer'
/usr/local/lib/libPNGwriter.a(pngwriter.cc.o): In function `pngwriter::read_png_info(_IO_FILE*, png_struct_def**, png_info_def**)':
pngwriter.cc:(.text+0x4fdf): undefined reference to `png_set_longjmp_fn'
collect2: error: ld returned 1 exit status
I'm still left clueless.
Thanks to john, I think I got it figured out. My guess is that the installation from the source (after the Spack installation) messed things up somehow. I reinstalled PNGwriter using Spack and, now apparently having all the pieces for the compilation command, was finally able to compile the example code.
Summary:
Source Spack
# For bash/zsh/sh
$ . spack/share/spack/setup-env.sh
# For tcsh/csh
$ source spack/share/spack/setup-env.csh
# For fish
$ . spack/share/spack/setup-env.fish
Install using Spack (skip if already installed)
spack install pngwriter
Load PNGwriter (I guess one needs to do this in every new terminal session)
spack load pngwriter
Compile (note that this isn't quite what the PNGwriter manual suggests)
g++ example.cpp -o example `freetype-config --cflags` -I/usr/local/include -L/usr/local/lib -lPNGwriter -lpng -lz -lfreetype
Good Day Everyone,
N.B - This problem has been solved - I have provided my own solution in the answer section however the solution provided by Jonathan is much shorter. Nevertheless, this was the following question I originally posted:
I am basically trying to compile a serial library (for UART communication) on Linux however I am not really sure how to correctly compile (I have mentioned what I have done so far below), any suggestions would be highly valuable. I am using the serialib library - which is composed of 2 main files (serialib.h and serialib.cpp) , you may directly view the source code of these files here (scroll all the way to the bottom and view the files in new tabs): http://serialib.free.fr/html/classserialib.html
I transferred these files (serialib.h and serialib.cpp) to my BeagleBone Black micro-controller which is running Debian (Wheezy) , g++/gcc (Debian 4.6.3-14) 4.6.3. I wrote my own program (uart.cpp is my file name) to access the functions provided by this library, this is what I wrote:
#include <iostream>
#include "serialib.h"
#ifdef __linux__
#define DEVICE_PORT "/dev/ttyO1"
#endif
int main()
{
serialib LS;
return 0;
}
So as you can see I am trying to access the 'seriallib' class. serialib.h, serialib.cpp and uart.cpp are all in the home directory. I also manually added the iostream library in serialib.cpp as I did not see it being declared in the original source code.
Now I am really unsure of how to compile such external libraries but so far I tried the following steps:
g++ -c -Wall -Werror -fPIC serialib.c to convert to PIC which gives the following error:
distcc[3142] (dcc_parse_hosts) Warning: /home/debian/.distcc/zeroconf/hosts contained no hosts; can't distribute work
distcc[3142] (dcc_zeroconf_add_hosts) CRITICAL! failed to parse host file.
distcc[3142] (dcc_build_somewhere) Warning: failed to distribute, running locally instead
g++ serialib.cpp -L /home/debian/serialib.h which gives the following error:
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf/crt1.o: In function _start':
(.text+0x30): undefined reference tomain'
collect2: ld returned 1 exit status
distcc[3210] ERROR: compile serialib.cpp on localhost failed
As of now I am still finding out how to compile this and if I manage to work this out then I'll post my solution here too. Once again any suggestion will be highly valuable. Thank you all :) .
g++ -c -Wall -Werror -fPIC serialib.c to convert to PIC which gives the following error:
The "error" is not an error, it's a warning, telling you that your distcc setup is broken, but that it compiled locally.
That command doesn't "convert to PIC", it compiles the file serialib.c and produces a compiled object file, serialib.o
g++ serialib.cpp -L /home/debian/serialib.h
This is just nonsense. It tries to build a program from serialib.cpp and use the directory /home/debian/serialib.h (which isn't a directory!) to find libraries.
You don't need to "compile a library" you can just compile both the source files and link them together into a program. Either:
g++ -c serialib.cpp
g++ -c uart.cpp
g++ serialib.o uart.o -o uart
Or all in one command:
g++ serialib.cpp uart.cpp -o uart
You should read An Introduction to GCC to understand the commands, not just enter bogus commands without understanding them.
I have found a solution to this problem, hope this helps for all the future readers with similar problems. I have my own source code uart.cpp (Given in the question) which I want to compile, the external library is serialib that contains two main files (serialib.h and serialib.cpp), you will want to replace the following commands with respect to the files you have
Step 1: Compiling with position independent code
g++ -c -Wall -Werror -fpic serialib.cpp
Step 2: Creating a shared library
g++ -shared -o libserialib.so serialib.o , here the library is libserialib.so.
Step 3: Linking your source code with library
g++ -L /home/debian -lserialib uart.cpp -o uart
g++ -L /home/debian -Wall -o test uart.cpp -lserialib
You may save the library at a different path and you may have a different name of course. Suppose you have a library called libabc.so at the directory /home/user/myDir then the commands will be like:
g++ -L /home/user/myDir -labc your_code.cpp -o your_code
g++ -L /home/user/myDir -Wall -o test your_code.cpp -labc
test is out own program, lserialib is actually looking for libserialib.so and not serialib.o as gcc/g++ assumes all libraries start with lib and end with .so or .a and you can see the same goes for labc as it will look for libabc.so thus it is important to make sure your library name begins with lib and ends with .so or .a
Step 4: Making library available at run time
Here we provide the path where the library is actually stored, I saved it in the directory /home/debian which is why my command looks like:
export LD_LIBRARY_PATH=/home/debian:$LD_LIBRARY_PATH
if your library is saved at /path/to/file then the command will look like:
export LD_LIBRARY_PATH=/path/to/file:$LD_LIBRARY_PATH
This is to help the loader find the shared library and to view this path: echo $LD_LIBRARY_PATH and to unset this: unset LD_LIBRARY_PATH
To execute the program type either ./test or ./uart and in case of any modification to the main source code (uart.cpp in this case) , simply repeat step 3. I found the following link very useful: http://www.cprogramming.com/tutorial/shared-libraries-linux-gcc.html . Thank you to all of you who took time to read this question and especially those who gave me suggestions. If anyone has more or better solutions, feel free to post them here to assist future readers :).
I use MinGW32 more specifically TDM-GCC-32. I have very simple project I link to one custom library but this error pops out:
>g++ -D_WIN32 -D_MINGW -lgdi32 -lgdiplus -Linterception/x86 -linterception main.cpp -o interceptor.exe
interception/x86/libinterception.a(dgnes00125.o):(.text+0x0): multiple definitio
n of `atexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2c0):
first defined here
interception/x86/libinterception.a(dgnes00109.o):(.text+0x0): multiple definitio
n of `_onexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2d0):
first defined here
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../../mingw32/bin/ld.exe: C:/TD
M-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o: bad reloc address 0x20 in
section `.eh_frame'
collect2.exe: error: ld returned 1 exit status
Commands I use to build the library:
gcc -DINTERCEPTION_EXPORT -D_WIN32 -D_MINGW -shared -o interception.dll interception.c
dlltool -z interception.def --export-all-symbol interception.dll
dlltool -d interception.def -l libinterception.a
I guess I have to use different options for compiling the library to avoid redefinitions..
The dlltool method I believe is currently deprecated. I can't fault you here though, as most of the available documentation still says to do it this way.
Gcc will link directly against .dll files, making .a files obsolete (at least for dealing with dll's - the only current reason to use a .a file is for static linking). You don't even have to specify the dll with the -l flag, although you have to specify the path of the dll if it's not in your current directory
C:\Users\burito>gcc main.o opengl32.dll -o main.exe
gcc: error: opengl32.dll: No such file or directory
C:\Users\burito>gcc main.o c:\Windows\system32\opengl32.dll -o main.exe
C:\Users\burito>
Ok, opengl32.dll is perhaps not a great example, but I hope I've given you the general idea.
I believe MSVC still needs its .lib files to use a .dll, for which there are several ways of making them if the library doesn't come with one.
In your specific case, the command that should work would be...
g++ -D_WIN32 -D_MINGW -lgdi32 -lgdiplus interception/x86/interception.dll main.cpp -o interceptor.exe
If for whatever reason you really do need to create a .a file from a .dll, the command that has worked for me is...
gendef interception.dll
dlltool -l interception.a -d interception.def -k -A
As the repository you linked does provide .dll files in its releases, you shouldn't have to build them yourself
I have downloaded and build the boost libraries with
bootstrap mingw
and
b2 toolset=gcc
and the libraries are created in
C:\Boost\boost_1_57_0\stage\lib
In eclipse I have added this directory as a library path
and added the library libboost_thread-mgw49-mt-1_57 with and without the .a on the end.
the g++ line looks like
g++ "-LC:\\Boost\\boost_1_57_0\\stage\\lib" -o MyThread.exe main.o MyThread.o -llibboost_thread-mgw49-mt-1_57
and I get the error message
ld.exe: cannot find -llibboost_thread-mgw49-mt-1_57 collect2.exe: error: ld returned 1 exit status
If I add the .a it is appended to the error message as expected.
what am I doing wrong?
Specify the library without the lib prefix (which is the UNIX convention):
g++ "-LC:\Boost\boost_1_57_0\stage\lib" -pthread -o MyThread.exe main.o MyThread.o -libboost_thread-mgw49-mt-1_57
There's even a chance that (with the help of some standard convention symlinks) you could just say -lboost_thread.
PS Don't forget to use -pthread as well
I am using Ubuntu and my IDE is Aptana 3.0
I am getting the following error when trying to build. The library libfcgi.a is located in /usr/local/lib/.
In the Library C++ Linker section of the project properties, I added /usr/local/lib/ to the search path and the file /usr/local/lib/libfcgi.a.
Why can I still not build?
**** Build of configuration Debug for project rtb ****
make all
Building target: rtb
Invoking: GCC C++ Linker
g++ -L/usr/local/lib -o"rtb" ./src/rtb.o -l/usr/local/lib/libfcgi.a
/usr/bin/ld: cannot find -l/usr/local/lib/libfcgi.a
collect2: ld returned 1 exit status
make: *** [rtb] Error 1
I think this may be what you want;
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o -lfcgi
-l<value> will automatically look in all folders listed with -L for a library named lib<value>.a or lib<value>.so, all you need is the '-lfcgi'.
Try "-lfcgi" instead
g++ -L/usr/local/lib -o"rtb" ./src/rtb.o -lfcgi
Your linker flag is wrong it needs to be -lfcgi and not the whole path with the "lib" prefix and the .a suffix.
You can change it by hand, or in Apatana. To do so you don't have to give him the full qualified path to your lib two times. ( You already gave him the search path, remember? ). Usually you define additional libraries just like this:
cfgi and your IDE does the rest to add it to the linker flags!
You should do
g++ -o "rtb" ./src/rtb.o -lfcgi
In the unlikely case that /usr/local/lib/ is not in your search path, you can either add that path in the command line like
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o -lfcgi
or put it in the environment variable LIBRARY_PATH before calling your compile command, e.g. with bash:
if [ -z "$LIBRARY_PATH" ];
then export LIBRARY_PATH=/usr/local/lib;
else export LIBRARY_PATH="$LIBRARY_PATH":/usr/local/lib;
fi
If you insist in giving the explicit file name, omit the -l:
g++ -L/usr/local/lib -o "rtb" ./src/rtb.o /usr/local/lib/libfcgi.a
However I'd advise against that because it's inflexible. If the issue is that there's another, incompatible version of the library installed, it's better to make sure that the correct one comes first in the search path (or even better, make sure that the wrong one isn't in the search path at all ― maybe even by removing it from the system).
That's for the help all....really appreciate it.
Here is the solution. I had to use -lfcgi++ and I added the
g++ -L/usr/local/include/ -lfcgi++ -o"rtb" ./src/rtb.o
The above was the output from aptanta console. I tried -lfcgi and did not work. Google search lead to using -lfcgi++.