You have to tell the compiler to actually link with the library you're using: you need an -l
option, probably something like -lgsl
. (Take the name of the .so
file, remove the .so
suffix and lib
prefix, and that's what to put after -l
.)
The -L
option tells the linker where to find libraries, but doesn't direct it to actually link with anything — just like the -I
option tells the compiler where to find headers, but doesn't actually #include
any code.