3.2.156 sprintf

sprintf 

FORMAT

, 

LIST

This function returns a string formatted by the usual printf conventions. The FORMAT string contains text with embedded field specifiers into which the elements of LIST are substituted, one per field. Field specifiers are roughly of the form:

%

m.nx

where the m and n are optional sizes whose interpretation depends on the type of field, and x is one of:

Code	Meaning
c	Character
d	Decimal integer
e	Exponential format floating-point number
f	Fixed point format floating-point number
g	Compact format floating-point number
ld	Long decimal integer
lo	Long octal integer
lu	Long unsigned decimal integer
lx	Long hexadecimal integer
o	Octal integer
s	String
u	Unsigned decimal integer
x	Hexadecimal integer
X	Hexadecimal integer with upper-case letters

The various combinations are fully documented in the manpage for printf(3) , but we'll mention that m is typically the minimum length of the field (negative for left justified), and n is precision for exponential formats and the maximum length for other formats. Padding is typically done with spaces for strings and zeroes for numbers. The * character as a length specifier is not supported. But, you can easily get around this by including the length expression directly into FORMAT , as in:

$width = 20; $value = sin 1.0;
foreach $precision (0..($width-2)) {
    $output_arr[$precision] = sprintf "%${width}.${precision}f", $value;
}