<p>Blog post: The history of Unix's ioctl and signal about window sizes <a href="https://utcc.utoronto.ca/~cks/space/blog/unix/WindowSizeIoctlAndSignal" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">utcc.utoronto.ca/~cks/space/bl</span><span class="invisible">og/unix/WindowSizeIoctlAndSignal</span></a> (in which a post from <span class="h-card" translate="no"><a href="https://adhd.irenes.space/@ireneista" class="u-url mention">@<span>ireneista</span></a></span> kind of nerd-sniped me and I kept digging)</p><p>tl;dr: SIGWINCH came from very early SunOS, and appears to have originally been intended for graphical programs (the early SunOS window system was partly kernel based). The TIOCGWINSZ ioctl is first officially documented in 4.3 BSD but may have been present in early SunOS too (it is in 3.5).</p>
