Perl printf 函数

perl printf函数例子，printf函数实例代码 - 打印解释，通过指定的格式格式到当前输出文件句柄值的列表LIST，或一个指定的文件句柄。

语法

printf FILEHANDLE FORMAT, LIST printf FORMAT, LIST

定义和用法

打印解释，通过指定的格式格式到当前输出文件句柄值的列表LIST，或一个指定的文件句柄。

实际上相当于打印FILEHANDLE的sprintf（FORMAT，LIST）

您可以使用printf打印的情况：如果你并不需要一个特定的输出格式。

以下是公认的格式转换。

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，有选择地调整输出格式的标志。这些被指定％和转换字母。它们显示在下面的表中：

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 - 失败

• 1 - 成功

例子

试试下面的例子：

#!/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;

这将产生以下结果：自己可尝试更多的选择。

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