How do you fix an undefined reference?

So when we try to assign it a value in the main function, the linker doesn’t find the symbol and may result in an “unresolved external symbol” or “undefined reference”. The way to fix this error is to explicitly scope the variable using ‘::’ outside the main before using it.

What is undefined reference to POW?

When we use the pow function or any other math functions from math header in c program on linux environment (RHEL, Fedora or CentOS), need to use -lm option for compilation. otherwise you will get undefined reference to pow error, when you compile below program with no -lm option.

What is the error undefined reference to main?

The error: undefined reference to ‘main’ in C program is a very stupid mistake by the programmer, it occurs when the main() function does not exist in the program. If you used main() function and still the error is there, you must check the spelling of the main() function.

What is an undefined symbol?

A symbol remains undefined when a symbol reference in a relocatable object is never matched to a symbol definition. Similarly, if a shared object is used to create a dynamic executable and leaves an unresolved symbol definition, an undefined symbol error results.

How do you fix undefined reference to POW in C?

a . You need to link your program with this library so that the calls to functions like pow() are resolved. This solved my issue.

How do you fix undefined symbol in C?

The error is produced by the linker, ld . It is telling you that the symbol pow cannot be found (is undefined in all the object files handled by the linker). The solution is to include the library which includes the implementation of the pow() function, libm (m for math).

Where is LIBM?

The standard system libraries are usually found in the directories ‘/usr/lib’ and ‘/lib’. For example, the C math library is typically stored in the file ‘/usr/lib/libm.

What is LIBM A?

The static version of the C math library is called libm. a is for “archive” in UNIX jargon). The corresponding dynamic version of the C math library is called libm.so (.