在 bash 中右对齐/填充数字
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right align/pad numbers in bash
提问by nedned
What's the best way to pad numbers when printing output in bash, such that the numbers are right aligned down the screen. So this:
在 bash 中打印输出时填充数字的最佳方法是什么，以便数字在屏幕上右对齐。所以这：
00364.txt with 28 words in 0m0.927s
00366.txt with 105 words in 0m2.422s
00367.txt with 168 words in 0m3.292s
00368.txt with 1515 words in 0m27.238
Should be printed like this:
应该像这样打印：
00364.txt with 28 words in 0m0.927s
00366.txt with 105 words in 0m2.422s
00367.txt with 168 words in 0m3.292s
00368.txt with 1515 words in 0m27.238
I'm printing these out line by line from within a for loop. And I will know the upper bound on the number of words in a file (just not right now).
我从 for 循环中一行一行地打印出来。而且我会知道文件中字数的上限（只是现在不是）。
回答by Suvesh Pratapa
For bash, use the printfcommand with alignment flags.
对于 bash，使用printf带有对齐标志的命令。
For example:
例如：
printf '%7s' 'hello'
Prints:
印刷：
hello
(Imagine 2 spaces there)
（想象那里有 2 个空格）
Now, use your discretion for your problem.
现在，用你的判断力来解决你的问题。
回答by Paused until further notice.
Here's a little bit clearer example:
这是一个更清晰的例子：
#!/bin/bash
for i in 21 137 1517
do
printf "...%5d ...\n" "$i"
done
Produces:
产生：
... 21 ...
... 137 ...
... 1517 ...
回答by test30
If you are interested in changing width dynamically, you can use printf's '%*s' feature
如果您对动态更改宽度感兴趣，可以使用 printf 的 '%*s' 功能
printf '%*s' 20 hello
which prints
哪个打印
hello
回答by Jonathan Cross
Here is a combination of answers above which removes the hard-coded string length of 5characters:
这是上述答案的组合，删除了5字符的硬编码字符串长度：
VALUES=( 21 137 1517 2121567251672561 )
MAX=1
# Calculate the length of the longest item in VALUES
for i in "${VALUES[@]}"; do
[ ${#i} -gt ${MAX} ] && MAX=${#i}
done
for i in "${VALUES[@]}"; do
printf "... %*s ...\n" $MAX "$i"
done
Result:
结果：
... 21 ...
... 137 ...
... 1517 ...
... 2121567251672561 ...
