Printf with %

 Format Specifiers

c	Character	a
d or i	Signed decimal integer	392
e E	Scientific notation (mantise/exponent) using e character	3.9265e+2
		3.9265E+2
f	Decimal floating point	392.65
g	Use the shorter of %e or %f	392.65
G	Use the shorter of %E or %f	392.65
o	Signed octal	610
s	String of characters	sample
u	Unsigned decimal integer	7235
x	Unsigned hexadecimal integer	7fa
X	Unsigned hexadecimal integer (capital letters)	7FA
p	Pointer address	B800:0000
n	Nothing printed. The argument must be a pointer to a signed int, where the number of characters written so far is stored.
%	A % followed by another % character will write % to stdout.

Integer
 %d    print as decimal integer
 %6d    print as decimal integer, at least 6 characters wide
Float
 %f    print as floating point
 %6f    print as floating point, at least 6 characters wide
 %.2f    print as floating point, 2 characters after decimal point
 %6.2f     print as floating point, at least 6 wide and 2 after decimal point

flags	description
-	Left-justify within the given field width; Right justification is the default (see width sub-specifier).
+	Forces to preceed the result with a plus or minus sign (+ or -) even for positive numbers. By default, only negative numbers are preceded with a - sign.
(space)	If no sign is going to be written, a blank space is inserted before the value.
#	Used with o, x or X specifiers the value is preceeded with 0, 0x or 0X respectively for values different than zero. Used with e, E and f, it forces the written output to contain a decimal point even if no digits would follow. By default, if no digits follow, no decimal point is written. Used with g or G the result is the same as with e or E but trailing zeros are not removed.
0	Left-pads the number with zeroes (0) instead of spaces, where padding is specified (see width sub-specifier).

width	description
(number)	Minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger.
*	The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.

.precision	description
.number	For integer specifiers (d, i, o, u, x, X): precision specifies the minimum number of digits to be written. If the value to be written is shorter than this number, the result is padded with leading zeros. The value is not truncated even if the result is longer. A precision of 0 means that no character is written for the value 0. For e, E and f specifiers: this is the number of digits to be printed after the decimal point. For g and G specifiers: This is the maximum number of significant digits to be printed. For s: this is the maximum number of characters to be printed. By default all characters are printed until the ending null character is encountered. For c type: it has no effect. When no precision is specified, the default is 1. If the period is specified without an explicit value for precision, 0 is assumed.
.*	The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.

length	description
h	The argument is interpreted as a short int or unsigned short int (only applies to integer specifiers: i, d, o, u, x and X).
l	The argument is interpreted as a long int or unsigned long int for integer specifiers (i, d, o, u, x and X), and as a wide character or wide character string for specifiers c and s.
L	The argument is interpreted as a long double (only applies to floating point specifiers: e, E, f, g and G).

additional arguments

Depending on the format string, the function may expect a sequence of additional arguments, each containing one value to be inserted instead of each %-tag specified in the format parameter, if any. There should be the same number of these arguments as the number of %-tags that expect a value.

Return Value

On success, the total number of characters written is returned.
On failure, a negative number is returned.
Examples:
printf("%A", b);
A              B                 output

c               'a'                 a
c                'A'               A

d       1977

ld      650000 

10d     1977      ^^^^^^1977 

010d    1977      0000001977

x       100       64     

o       100       144

#x      100       0x64

#o      100       064

4.2f    3.1416    3.14  

+.0e    3.1416    +3e+000

E       3.1416    3.141600E+000

*d      5,10      ^^^10

+ and -

printf("%5s", 'foo');  # prints '  foo'
printf("%-5s", 'foo');  # prints 'foo  ' 

' ' (a space): To specify that a blank should be left before a
positive number.
printf("% d", 7);  # prints ' 7'
printf("% d", -7);  # prints '-7'

Precision

printf("%.3d", 7);  # prints '007'
 

string :

printf("%.3s", 'foobar');          # prints 'foo'

printf("%.3s", 'foobar');   # prints 'foo'

printf("%.10s", 'foobar');   # prints 'foobar'

printf("%5.5s %5.5s", 'foobar', 'baz');  # prints 'fooba   baz'
 

printf("%.2f", 3.66666);          # prints '3.66' 

printf("%.2f", 9.333333);          # prints '9.34'

printf("%.2f", 9);           # prints '9.00'

printf("%.3f", 7);           # prints 007

Miscellaneous

The character 'V' will interpret an integer as Perl's standard integer
type.
printf("%Vd", 7);  # prints '7'