The convention is that all fortran subroutines have an underscore at the end. In your C file, declare it as long read_block_, and in your fortran code call it 'read_block'. ->Both program and function compile, but when I try to link, I get the ->message, "undefined reference to 'read_block_'." The linker is asking for a symbol called read_block_. Not read_block. HTH, bud
