main.c:(.text+0x23c): undefined reference to `memset'

This error message indicates that there is a call to the standard C library function `memset()` in the `main.c` file, but the linker is unable to find the definition of this function.

To resolve the issue, you need to include the header file `<string.h>` where the declaration of `memset()` is located and link your program with the standard C library by adding the `-lc` option to your compiler command.

For example, if you are using the GCC compiler, you can compile and link your program with the following command:

gcc main.c -o myprogram -lc

This will link your program with the standard C library and resolve the undefined reference to `memset()`.