BASIC and Perl had or have something like that too. IIRC, Perl copied it from BASIC, because BASIC came much before Perl. And, again, IIRC, I've read about th

BASIC and Perl had or have something like that too. IIRC, Perl copied it from BASIC, because BASIC came much before Perl. And, again, IIRC, I've read about the shar (shell archive) method that someone else commented about in this thread (and which even has a Wikipedia entry), in either the classic Kernighan and Pike book, The Unix Programming Environment (which I've recommended here multiple times before), or in some Unix man pages, long ago. So it's quite an old method.