Header Purpose
assert.hDefines the assert() macro
ctype.hCharacter handling
errno.hError reporting
float.hDefines implementation-dependent floating-point limits
limits.hdependent limits
locale.hLocalization
math.hmath library
setjmp.hNonlocal jumps
signal.hSignal handling
stdarg.hVariable argument lists
stddef.hConstants
stdio.hI/O system
stdlib.hMiscellaneous declarations
string.hstring functions
time.hsystem time functions
From
C: The Complete Reference, Fourth Edition
by Herbert Schildt
McGraw-Hill/Osborne 2000