POSIX.1-2001 Utilities[1] and POSIX.1-2008 Utilities[2] both list the commands "bc" and "ed" to be part of POSIX.
Yet, in a brand new Debian installation (version 10 for example), these commands are missing by default: $ bc bash: bc: command not found $ ed bash: ed: command not found Why does Debian not include these commands by default? Of course, I can install them with "apt-get" and I did that. apt-get install bc ed The "bc" binary is only 87K in size. The entire package including the man page and documentation is only 209K in size. Similarly the "ed" binary is only 55K in size. The entire package is only 93K in size. What good reason is there not to include these tiny packages even though they are specified in POSIX? [1]: https://pubs.opengroup.org/onlinepubs/009695399/idx/utilities.html [2]: https://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html
