Undefined reference to a static member
You need to define _frequency in the .cpp file. i.e.
undefined-reference
gcc: undefined reference to
However, avpicture_get_size is defined. No, as the header (<libavcodec/avcodec.h>) just declares it. The definition is in the library itself. So you might like to add the linker option to link libavcodec when invoking gcc: Please also note that libraries need to be specified on the command line after the files needing them: Not like this: Referring to Wyzard‘s comment, the complete command might look like … Read more
Undefined Reference issues using Semaphores
I am playing around with using Semaphores, but I keep encountering Undefined Reference warnings, thus causing my code not to work. I pulled example code from a text, but was having issues with some of their syntax, so I went to POSIX’s semaphore tutorial and changed things around to their syntax and as a result … Read more
libpthread.so.0: error adding symbols: DSO missing from command line
You should mention the library on the command line after the object files being compiled: Explanation: the linking is dependent on the order of modules. Symbols are first requested, and then linked in from a library that has them. So you have to specify modules that use libraries first, and libraries after them. Like this: Moreover, in … Read more
In C programming, what is `undefined reference`error, when compiling?
When you link the program you need to give both Main.o and Person.o as inputs. Build usually is done in two steps (1) compilation and (2) linking. To compile your sources do: Or in one line: Then the resulting object files must be linked into a single executable: For small projects, of a few compilation … Read more
C error: undefined reference to function, but it IS defined
How are you doing the compiling and linking? You’ll need to specify both files, something like: …so that it knows to link the functions from both together. With the code as it’s written right now, however, you’ll then run into the opposite problem: multiple definitions of main. You’ll need/want to eliminate one (undoubtedly the one in … Read more
C++ undefined reference to defined function
The declaration and definition of insertLike are different In your header file: void insertLike(const char sentence[], const int lengthTo, const int length, const char writeTo[]); In your ‘function file’: void insertLike(const char sentence[], const int lengthTo, const int length,char writeTo[]); C++ allows function overloading, where you can have multiple functions/methods with the same name, as long as they … Read more
What is an undefined reference/unresolved external symbol error and how do I fix it?
Compiling a C++ program takes place in several steps, as specified by 2.2 (credits to Keith Thompson for the reference): The precedence among the syntax rules of translation is specified by the following phases [see footnote]. Physical source file characters are mapped, in an implementation-defined manner, to the basic source character set (introducing new-line characters for end-of-line indicators) … Read more
What is an undefined reference/unresolved external symbol error and how do I fix it?
Compiling a C++ program takes place in several steps, as specified by 2.2 (credits to Keith Thompson for the reference): The precedence among the syntax rules of translation is specified by the following phases [see footnote]. Physical source file characters are mapped, in an implementation-defined manner, to the basic source character set (introducing new-line characters for end-of-line indicators) … Read more