преобразование форматированного вывода (formatted output conversion)
Стандарты (Conforming to)
fprintf
(), printf
(), sprintf
(), vprintf
(), vfprintf
(),
vsprintf
(): POSIX.1-2001, POSIX.1-2008, C89, C99.
snprintf
(), vsnprintf
(): POSIX.1-2001, POSIX.1-2008, C99.
The dprintf
() and vdprintf
() functions were originally GNU
extensions that were later standardized in POSIX.1-2008.
Concerning the return value of snprintf
(), SUSv2 and C99
contradict each other: when snprintf
() is called with size=0 then
SUSv2 stipulates an unspecified return value less than 1, while
C99 allows str to be NULL in this case, and gives the return
value (as always) as the number of characters that would have
been written in case the output string has been large enough.
POSIX.1-2001 and later align their specification of snprintf
()
with C99.
glibc 2.1 adds length modifiers hh
, j
, t
, and z
and conversion
characters a
and A
.
glibc 2.2 adds the conversion character F
with C99 semantics, and
the flag character I
.