c - Linker symbols not found -

i'm trying compile i've fetched off of github gcc:

users-mbp:chip-8-emulator user$ gcc -o chip8 chip8.c undefined symbols architecture x86_64:   "_sdl_delay", referenced from:       _chip8_draw in chip8-bc89fc.o   "_sdl_flip", referenced from:       _chip8_draw in chip8-bc89fc.o   "_sdl_getkeystate", referenced from:       _chip8_execute in chip8-bc89fc.o       _chip8_prec in chip8-bc89fc.o   "_sdl_getvideosurface", referenced from:       _chip8_draw in chip8-bc89fc.o   "_sdl_init", referenced from:       _chip8_prepare in chip8-bc89fc.o   "_sdl_locksurface", referenced from:       _chip8_draw in chip8-bc89fc.o   "_sdl_pollevent", referenced from:       _chip8_prepare in chip8-bc89fc.o       _chip8_prec in chip8-bc89fc.o   "_sdl_setvideomode", referenced from:       _chip8_prepare in chip8-bc89fc.o   "_sdl_unlocksurface", referenced from:       _chip8_draw in chip8-bc89fc.o ld: symbol(s) not found architecture x86_64 clang: error: linker command failed exit code 1 (use -v see invocation) 

the error seems issue sdl library in case, i've had exact same issue several other little projects treid compile. before compiling, installed sdl libs , checked there:

users-mbp:chip-8-emulator user$ ls /usr/local/lib/ ...            libsdl-1.2.0.dylib        libsdl.a                  libsdl.dylib              libsdlmain.a ... 

after lots of googling seems i'm not 1 problem , couldn't find solution worked. seems osx doesn't include /use/local/lib in default linker paths.

how can fix (a permanent solution welcome)?

edit following suggestion user alex tried $ gcc -o chip8 -l/usr/local/lib chip8.c. error , output identical above.

you'll want add -l/usr/local/lib -lsdl gcc invocation.

as more permanent solution, convention of os x, , strictly speaking /usr/local/lib non-standard installation location.