Well, after some suggestions from Bruno, I fixed up the "mk" script to be more portable, tho I haven't tried it on Solaris' /bin/sh. Probably won't work. I don't have access. It might work. It remains a program and not a library function, too. One interesting thing I discovered:
$ errno . | head -n4 ; echo '[...]';errno . | tail -n4 looking for matches to: '.' 1 (EPERM. . . . . ) == Operation not permitted 2 (ENOENT . . . . ) == No such file or directory 3 (ESRCH. . . . . ) == No such process [...] 130 (EOWNERDEAD . . ) == Owner died 131 (ENOTRECOVERABLE) == State not recoverable 132 (ERFKILL. . . . ) == Unknown error 132 Oops.
errno.txz
Description: application/xz-compressed-tar