Perl printf 函數

perl printf函數例子，printf函數實例代碼 - 打印解釋，通過指定的格式格式到當前輸出文件句柄值的列表LIST，或一個指定的文件句柄。

語法

printf FILEHANDLE FORMAT, LIST printf FORMAT, LIST

定義和用法

打印解釋，通過指定的格式格式到當前輸出文件句柄值的列表LIST，或一個指定的文件句柄。

實際上相當於打印FILEHANDLE的sprintf（FORMAT，LIST）

您可以使用printf打印的情況：如果你並不需要一個特定的輸出格式。

以下是公認的格式轉換。

Format	Result
%%	A percent sign
%c	A character with the given ASCII code
%s	A string
%d	A signed integer (decimal)
%u	An unsigned integer (decimal)
%o	An unsigned integer (octal)
%x	An unsigned integer (hexadecimal)
%X	An unsigned integer (hexadecimal using uppercase characters)
%e	A floating point number (scientific notation)
%E	A floating point number, uses E instead of e
%f	A floating point number (fixed decimal notation)
%g	A floating point number (%e or %f notation according to value size)
%G	A floating point number (as %g, but using .E. in place of .e. when appropriate)
%p	A pointer (prints the memory address of the value in hexadecimal)
%n	Stores the number of characters output so far into the next variable in the parameter list

Perl也支持，有選擇地調整輸出格式的標誌。這些被指定％和轉換字母。它們顯示在下麵的表中：

Flag	Result
space	Prefix positive number with a space
+	Prefix positive number with a plus sign
-	Left-justify within field
0	Use zeros, not spaces, to right-justify
#	Prefix non-zero octal with .0. and hexadecimal with .0x.
number	Minimum field width
.number	Specify precision (number of digits after decimal point) for floating point numbers
l	Interpret integer as C-type .long. or .unsigned long.
h	Interpret integer as C-type .short. or .unsigned short.
V	Interpret integer as Perl.s standard integer type
v	Interpret the string as a series of integers and output as numbers separated by periods or by an arbitrary string extracted from the argument when the flag is preceded by *.

返回值

• 0 - 失敗

• 1 - 成功

例子

試試下麵的例子：

#!/usr/bin/perl -w
#by www.gitbook.net

printf "%d\n", 3.1415126;
printf "The cost is \$%6.2f\n",499;
printf "Perl's version is v%vd\n",%^V;
printf "d\n", 20;

這將產生以下結果：自己可嘗試更多的選擇。

3
The cost is $499.00
Perl's version is v
0020