val fprintf: out_channel -> ('a, out_channel, unit) format -> 'a
The format is a character string which contains two types of objects: plain characters, which are simply copied to the output channel, and conversion specifications, each of which causes conversion and printing of one argument.
Conversion specifications consist in the % character, followed
by optional flags and field widths, followed by one conversion
character. The conversion characters and their meanings are:
d or i: convert an integer argument to signed decimal
u: convert an integer argument to unsigned decimal
x: convert an integer argument to unsigned hexadecimal,
using lowercase letters.
X: convert an integer argument to unsigned hexadecimal,
using uppercase letters.
s: insert a string argument
c: insert a character argument
f: convert a floating-point argument to decimal notation,
in the style dddd.ddd
e or E: convert a floating-point argument to decimal notation,
in the style d.ddd e+-dd (mantissa and exponent)
g or G: convert a floating-point argument to decimal notation,
in style f or e, E (whichever is more compact)
b: convert a boolean argument to the string true or false
a: user-defined printer. Takes two arguments and apply the first
one to outchan (the current output channel) and to the second
argument. The first argument must therefore have type
out_channel -> 'b -> unit and the second 'b.
The output produced by the function is therefore inserted
in the output of fprintf at the current point.
t: same as %a, but takes only one argument (with type
out_channel -> unit) and apply it to outchan.
Refer to the C library printf function for the meaning of
flags and field width specifiers.
If too few arguments are provided, printing stops just before converting the first missing argument.
val printf: ('a, out_channel, unit) format -> 'a
val eprintf: ('a, out_channel, unit) format -> 'a
val sprintf: ('a, unit, string) format -> 'a