Formatted print into a string
Returns a string formatted by the usual printf() conventions of the C
library function sprintf(). See sprintf(3) or printf(3) on your system
for an explanation of the general principles.
Perl does its own sprintf() formatting -- it emulates the C
function sprintf(), but it doesn't use it (except for floating-point numbers, and even
then only the standard modifiers are allowed). As a result, any non-standard extensions in your local sprintf()
are not available from Perl.
Perl's sprintf() permits the following universally-known conversions:
%% a percent sign
%c a character with the given number
%s a string
%d a signed integer, in decimal
%u an unsigned integer, in decimal
%o an unsigned integer, in octal
%x an unsigned integer, in hexadecimal
%e a floating-point number, in scientific notation
%f a floating-point number, in fixed decimal notation
%g a floating-point number, in %e or %f notation
In addition, Perl permits the following widely-supported conversions:
%X like %x, but using upper-case letters
%E like %e, but using an upper-case "E"
%G like %g, but with an upper-case "E" (if applicable)
%p a pointer (outputs the Perl value's address in hexadecimal)
%n special: *stores* the number of characters output so far
into the next variable in the parameter list
Finally, for backward (and we do mean ``backward'') compatibility, Perl permits these unnecessary but widely-supported
%i a synonym for %d
%D a synonym for %ld
%U a synonym for %lu
%O a synonym for %lo
%F a synonym for %f
Perl permits the following universally-known flags between the
% and the conversion letter:
space prefix positive number with a space
+ prefix positive number with a plus sign
- left-justify within the field
0 use zeros, not spaces, to right-justify
# prefix non-zero octal with "0", non-zero hex with "0x"
number minimum field width
.number "precision": digits after decimal point for
floating-point, max length for string, minimum length
l interpret integer as C type "long" or "unsigned long"
h interpret integer as C type "short" or "unsigned short"
There is also one Perl-specific flag:
V interpret integer as Perl's standard integer type
Where a number would appear in the flags, an asterisk (``
*'') may be used instead, in which case
Perl uses the next item in the parameter list as the given number (that is, as the field width or precision). If
a field width obtained through ``
*'' is negative, it has the same effect as the ``
use locale is in effect, the character used for the decimal point in formatted real numbers
is affected by the LC_NUMERIC locale. See the perllocale manpage.