comp.lang.c FAQ list · Question 13.24

Q: I'm trying to port this old program. Why do I get ``undefined external'' errors for some library functions?

A: Some old or semistandard functions have been renamed or replaced over the years;
if you need:/you should instead:

index: use strchr.
rindex: use strrchr.
bcopy: use memmove, after interchanging the first and second arguments (see also question 11.25).
bcmp: use memcmp.
bzero: use memset, with a second argument of 0.