functions to lock and unlock pages  (3.4.3 p76)
character class determination for wide characters  (4.3 p82)
collation functions  (5.6 p109)
trivial encryption  (5.10 p124)
encode binary data  (5.11 p125)
argz and envz vectors  (5.12 p127)
characer-set handling  (6 p133)
locales and internationalisation  (7 p181)
mathematics  (8 p243)
arithmetic functions  (9 p243)
date and time  (10 p277)
message translation  (11 p315)
searching and sorting  (12 p343)
pattern matching  (13 p355)
the basic program–system interface  (14 p379)
input/output overview  (15 p429)
debugging support  (16 p435)
input/output on streams  (17 p439)

add strstarts, strends, wcsstarts, wcsends as
  faster specialised alternatives to strstr.