The standard function in the
C programming
language library for printing formatted output.
The first argument is a format string which may contain
ordinary characters which are just printed and "conversion
specifications" - sequences beginning with '%' such as %6d
which describe how the other arguments should be printed, in
this case as a six-character decimal integer padded on the
right with spaces.
Possible conversion specifications are d, i or u (decimal
integer), o (
octal), x, X or p (
hexadecimal), f
(
floating-point), e or E (
mantissa and
exponent,
e.g. 1.23E-22), g or G (f or e format as appropriate to the
value printed), c (a single character), s (a string), %
(i.e. %% - print a % character). d, i, f, e, g are signed,
the rest are unsigned.
The variant
fprintf prints to a given output stream and
sprintf stores what would be printed in a string variable.
Unix manual page: printf(3).