My punishment for smarting off to the libc-alpha list is that I have to
admit an error.

At 2023-01-04T14:19:23-0600, G. Branden Robinson wrote:
> The b in bzero() [is] for Bad BSD Bogosity.  [...] Like index() and
> rindex() it is duplicative.

While BSD did hang on to {r,}index for a long time, I was digging around
in libc history while amiably reading C. D. Perez's "A Guide to the C
Library for Unix Users" (ca. 1981)[1] and found that I have to correct
myself...and possibly the Linux man-pages documents for them.

They date all the way back to V7 Unix and antedate str{r,}chr().

https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/index.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/rindex.c

Mea culpa.

Alex, in your current mission you might find entertainment of the
cerebral hemorrhage-causing variety in some of the following files.

https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strcat.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strcmp.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strcpy.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strlen.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strncat.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strncmp.c
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/libc/gen/strncpy.c

Regards,
Branden

[1] https://www.tuhs.org/Archive/Documentation/Manuals/Unix_4.0/Volume_1/D.1.2_A_Guide_to_the_C_Library.pdf