Linux Shell printf命令

在Linux shell中，printf命令用于格式化输出字符串或数字。它比echo命令更加灵活，可以自定义输出的格式，包括使用转义字符，指定输出宽度和小数位数等。

下面是一些常用的printf命令示例：

格式化字符串

printf "Hello, %s!\n" "world"
输出：Hello, world!

指定输出宽度

printf "%-10s %-10s %-10s\n" "Name" "Age" "Gender"
printf "%-10s %-10s %-10s\n" "John" "30" "Male"
printf "%-10s %-10s %-10s\n" "Alice" "25" "Female"
输出：

Name       Age        Gender    
John       30         Male      
Alice      25         Female   

指定小数位数

printf "The value of PI is approximately %0.2f\n" 3.141592653589793
输出：The value of PI is approximately 3.14

转义字符

printf "This is a tab:\t\tand this is a newline:\n"
输出：
This is a tab:           and this is a newline:

格式化数字

printf "Decimal: %d, Hexadecimal: %x, Octal: %o\n" 10 10 10
输出：Decimal: 10, Hexadecimal: a, Octal: 12

注意：printf命令中的格式化字符串用双引号括起来，而且每个格式化参数都以百分号（%）开头。