There is also a neat little BSD extension, also supported on a number of other Unix-like systems and GNU userspace (i.e. glibc, but also other libcs like Musl):

There is also a neat little BSD extension, also supported on a number of other Unix-like systems and GNU userspace (i.e. glibc, but also other libcs like Musl): extern char *__progname; which holds the program name without the (optional) invocation path in front of it. Basically the last path component of argv[0].