linux printf在命令行中使用,该命令用于格式化打印数据;printf的命令格式是“printf FORMAT [ARGUMENT]...printf OPTION”,其中“help”选项表示显示帮助信息,“version”选项表示显示版本信息。
本教程操作环境:linux5.9.8系统、Dell G3电脑。
linux printf 命令
1.命令简介
printf 格式化打印数据。
printf 与 C printf(3) 控制格式类似,具体也可以参考 printf(3) 的格式化控制字符。
2.命令格式
printf FORMAT [ARGUMENT]... printf OPTION
3.选项说明
--help 显示帮助信息。 --version 显示版本信息。
FORMAT 格式部分和 C printf(3) 一样。
%b 相对应的参数被视为含有要被处理的转义序列之字符串。 %c ASCII 字符。显示相对应参数的第一个字符 %d, %i 十进制整数 %e, %E, %f 浮点格式。 %g %e或%f转换,看哪一个较短,则删除结尾的零。 %G %E或%f转换,看哪一个较短,则删除结尾的零。 %o 不带正负号的八进制值。 %s 字符串。 %u 不带正负号的十进制值。 %x 不带正负号的十六进制值,使用a至f表示10至15。 %X 不带正负号的十六进制值,使用A至F表示10至15。 %% 字面意义的%
printf 支持的转义字符。
\" 双引号。\a 警告字符,通常为 ASCII 的 BEL 字符。\b 后退。\c 不显示输出结果中任何结尾的换行字符,而且任何留在参数里的字符、任何接下来的参数以及任何留在格式字符串中的字符都被忽略。\f 换页。\n 换行。\r 回车。\t 水平制表符。\v 垂直制表符。\\ 反斜杠字符。
4.常用示例
(1)输出字符串。
printf "hello world\n"hello world
(2)输出字符串不换行。
printf "hello world"hello world
(3)格式控制输出。
printf "hello %s\n" world hello world
(4)格式控制输出,并控制宽度。
printf "%-10s %-8s %-4s\n" 姓名 性别 "体重(kg)"姓名 性别 体重(kg)printf "%-10s %-8s %-4.2f\n" 杨过 男 68.6543杨过 男 68.65
%-10s 指一个宽度为10个字符(-表示左对齐,没有则表示右对齐),任何字符都会被显示在10个字符宽的字符内,如果不足则自动以空格填充,超过也会将内容全部显示出来。
%-4.2f 指格式化为小数,其中 .2 指保留 2 位小数。
(5)格式控制字符串也可用单引号括住。
printf '%d %s\n' 1 "hello world"1 hello world
(6)输出数字。
printf "%d %f %e\n" 1 1.000000001 1.0000000011 1.000000 1.000000e+01
小数位如果太长(数字总长度超过 8) 将被截断,我们可以指定小数位数。
printf "%d %.10f %e\n" 1 1.000000001 1.0000000011 1.0000000010 1.000000e+00
(7)输出百分比。对 % 进行转义即可。
printf "%d%%\n" 80
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