Video: C Programming on System 6 - User Authentication and Telnet Negotiation

posted on dec 10th, 2021 with tags mac, retrocomputing, and video
part of C Programming on System 6 series

I review some recent commits covering user authentication and telnet negotiation, then write some ANSI output code and a broken function for returning a number’s ordinal suffix.

Video notes:

  • sha2.c
  • strlcpy
  • Telnet Protocol Specification
  • xorshift32
  • Of course after reviewing my video, I realized the ordinal function I wrote was wrong for values over 20. The new code is:

      char *
      ordinal(unsigned short n)
          static char ordbuf[8];
          switch (n % 100) {
          case 11:
          case 12:
          case 13:
              sprintf(ordbuf, "%dth", n);
              switch (n % 10) {
              case 1:
                  sprintf(ordbuf, "%dst", n);
              case 2:
                  sprintf(ordbuf, "%dnd", n);
              case 3:
                  sprintf(ordbuf, "%drd", n);
                  sprintf(ordbuf, "%dth", n);
          return ordbuf;

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