> Is this related to the a.out file that gcc outputs if you don't specify a filename with -o? Yes, it is historically related. The file format is the descenda

> Is this related to the a.out file that gcc outputs if you don't specify a filename with -o? Yes, it is historically related. The file format is the descendant of binary format of the first C compiler, that already produced a.out files by default. Today in linux you typically get an ELF, but is still called like that.