printf format specifier

general

%[flags][width][.precision][length]specifier

flag

Flag	Description
-	Left-justify: The result is left-aligned within the specified field width. By default, it is right-aligned.
+	Sign: The result of a signed conversion will always begin with a sign (+ or -). By default, only negative values have a sign.
(space)	Space: If the first character of a signed conversion is not a sign, a space is prepended. This is ignored if the + flag is present.
#	Alternate Form: For o, the output is prefixed with 0. For x and X, it’s prefixed with 0x and 0X respectively. For a, A, e, E, f, F, g, and G, the output will always contain a decimal point.
0	Zero-padding: For numeric types, the output is padded with leading zeros instead of spaces to fill the field width. This is ignored if the - flag is present.

width

The width sub-specifier sets the minimum number of characters to be printed.

Width	Description
number	A non-negative integer specifying the minimum number of characters to print. If the printed value is shorter, it is padded with spaces (or zeros if the 0 flag is used).
*	The width is not specified in the format string itself, but as an additional integer argument preceding the argument to be formatted.

precision

Precision	Description
.number	For integer specifiers (d, i, u, o, x, X), it specifies the minimum number of digits to be written. For e, E, and f, it is the number of digits to appear after the decimal point. For g and G, it’s the maximum number of significant digits. For s, it’s the maximum number of characters to be printed.
.*	The precision is not specified in the format string itself, but as an additional integer argument preceding the argument to be formatted.

length

Modifier	For Integer Specifiers (d, i, u, o, x, X)	For Floating-Point Specifiers (f, e, g, a)
h	short int or unsigned short int	-
hh	signed char or unsigned char	-
l	long int or unsigned long int	-
ll	long long int or unsigned long long int	-
L	-	long double
j	intmax_t or uintmax_t	-
z	size_t or the corresponding signed type	-
t	ptrdiff_t or the corresponding unsigned type	-

specifier

Specifier	Data Type	Output Format
%c	char	A single character.
%s	char*	A string of characters.
%d or %i	int	Signed decimal integer.
%u	unsigned int	Unsigned decimal integer.
%o	unsigned int	Unsigned octal integer.
%x	unsigned int	Unsigned hexadecimal integer (lowercase letters).
%X	unsigned int	Unsigned hexadecimal integer (uppercase letters).
%f	double	Decimal floating-point number.
%F	double	Decimal floating-point number (uppercase ‘INF’ and ‘NAN’).
%e	double	Scientific notation (lowercase ‘e’).
%E	double	Scientific notation (uppercase ‘E’).
%g	double	Uses the shorter of %f or %e.
%G	double	Uses the shorter of %F or %E.
%a	double	Hexadecimal floating-point number (lowercase ‘p’).
%A	double	Hexadecimal floating-point number (uppercase ‘P’).
%p	void*	Pointer address.
%n	int*	The number of characters written so far is stored in the integer pointed to by the argument. Nothing is printed.
%%	None	A literal ‘%’ character is printed.