This comes of big help, because it represents the set of standard utilities available on all Unix-like systems. Now, I wonder if there is something Unix-like that doesn’t support one of these.
I think the problem is not so much the availability of the tools but the slight differences. The GNU version of some command is slightly different than the BSD one and Solaris is different again.
I agree. Still, I’m excited to learn what the standard tools are and what flags should be supported at minimum.
I guess Plan 9 would be a big example (notoriously lacks find), or am I misunderstanding you?
I think I wasn’t clear enough with my previous comment, sorry if you misundertood me. What I tried to say, is that if someone knows a Unix (want-to-be) system not supporting some of these standard tools. Plan 9 is different, because it is not Unix-like per sé.
When I worked with QNX (a real time, microkernel) it came with a userland that was very much like Unix. OS-9 (not the one from Apple but a different OS-9, originally for the 6809, versions then available for the 68000 and 80386) was also a Unix-like operating system.