bash 在 .txt 文件中查找最长的行并用“空格”将所有行填充到该长度？
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Find Longest Line in a .txt File and fill all Lines to that Length with 'blank Spaces'?
提问by noexpert
How can I find the longest line in a .txt file and then fill all other lines at their end to that length with blank spaces?
如何在 .txt 文件中找到最长的行，然后用空格将其末尾的所有其他行填充到该长度？
My guess is this is easy to answer. I know very little about using the awk, paste command and such. Maybe someone can help me out. Thanks!
我的猜测是这很容易回答。我对使用 awk、paste 命令等知之甚少。也许有人可以帮助我。谢谢！
A little more specific... so far I can do the following. This would get the longest Line from a .txt File:
更具体一点......到目前为止，我可以做到以下几点。这将从 .txt 文件中获得最长的行：
awk '{ if (length(awk 'length <= 50 { printf "%-50s\n",pr -W 80 -mtT file1 file2
}' in.txt > out.txt
) > max) {max = length(pr --page-width=80 --merge --omit-header --omit-pagination file1 file2
); maxline = # Measure the longest line in the file
maxlen=`wc -L filename.txt | cut -d ' ' -f 1`
# Pad each line to $maxlen characters
while read line
do
printf "%-${maxlen}s\n" "$line" >> outfile.txt
done < filename.txt
} } END { print maxline }' in.txt
This fills the lines with blank spaces (till 50):
这用空格填充行（直到 50）：
maxlen=0
while read line
do
thislen=`echo $line | wc -c`
[ $[$thislen>$maxlen] ] && maxlen=$thislen
done < filename.txt
I just don't know to pass the value from one line to the other.
我只是不知道将值从一行传递到另一行。
Why am I asking this? I want to merge two .txt files using the paste command. Text B will be positioned to the right of Text A. Lines in Text A will have different lengths. So if there are not enough blank spaces the layout isn't right.
我为什么要问这个？我想使用 paste 命令合并两个 .txt 文件。文本 B 将位于文本 A 的右侧。文本 A 中的行将具有不同的长度。所以如果没有足够的空格，布局就不正确。
回答by Ron Savage
Usually I find that this type of question is a result of this thought process:
通常我发现这类问题是这种思考过程的结果：
- I am trying to solve problem A
- I think doing process B will solve A
- I will ask how to achieve process B
- 我正在尝试解决问题 A
- 我认为做过程B会解决A
- 请问怎么实现过程B
You will get literal answers on how to achieve process B - but if you include the context of problem A, you will get better answers and probably one that solves problem A in a simpler manner than process B.
您将获得有关如何实现流程 B 的字面答案——但如果您包括问题 A 的上下文，您将获得更好的答案，并且可能以比流程 B 更简单的方式解决问题 A。
So, what problem are you trying to solve by making all the lines in a file the same length?
那么，通过使文件中的所有行长度相同，您试图解决什么问题？
回答by Paused until further notice.
This is all you need:
这就是你所需要的：
$ more file
jlsf
slf
asdfasfs
sd
$ awk 'FNR==NR{t=(length>=t)?length:t;next}length<t{for(o=1;o<=t-length;o++)s=s "|";while read line
do
printf "%-${max}s\n" $line
done < in.txt > out.txt
=maxLen = 0
infile = open("file.txt", 'r')
outfile = open("out.txt", 'w')
for line in infile:
if len(line)>maxLen: maxLen = len(line)
infile.seek(0)
for line in infile:
rawline = line.strip('\r\n')
out.write (rawline + ''.join([' ' for i in range(maxLen-len(rawline))]) + "\n")
infile.close ()
outfile.close ()
s;s=""}1' file file
jlsf||||
slf|||||
asdfasfs
sd||||||
Or, more verbosely:
或者，更详细地说：
##代码##Vary the number to change the layout of the result.
改变数字以改变结果的布局。
回答by bta
You can use wcto count the number of characters in a line. Measure all lines in the file to find the longest length. For all other files, (max length - line length) gives you the number of space characters to print at the end of the line (which you can do with printf).
您可以使用wc来计算一行中的字符数。测量文件中的所有行以找到最长的长度。对于所有其他文件， (max length - line length) 为您提供要在行尾打印的空格字符数（您可以使用printf）。
Update:Is using awka requirement? If not, try this:
更新：使用awk要求吗？如果没有，试试这个：
Edit #2:If you don't have the -Loption to wc, you can calculate the length of the longest line using the following loop:
编辑 #2：如果您没有-L选项wc，则可以使用以下循环计算最长线的长度：
The ending value of $maxlenwill be the length of the longest line.
的结束值$maxlen将是最长行的长度。
回答by ghostdog74
here's how one way to it with just awk.
这是仅使用 awk 的一种方法。
##代码##Change "|" to spaces as desired.
更改“|” 到所需的空间。
回答by mob
wc -Lor wc --max-line-lengthcomputes and displays the length of the longest line in the input (may not be available on all versions of wc).
wc -L或wc --max-line-length计算并显示输入中最长行的长度（可能不适用于 的所有版本wc）。
With the max line length in some variable (say, $max), run
使用某个变量中的最大行长（例如，$max），运行
回答by S..
If 'shell scripting' can include Python scripts, something like this:
如果“shell 脚本”可以包含 Python 脚本，则如下所示：
##代码##Fixing any off-by-one errors is left as an exercise for the reader! :-)
修复任何一个错误的错误留给读者作为练习！:-)
回答by Chris Koknat
You could combine your original ideas:
你可以结合你的原始想法：
awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt
awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt
awk 'length <= 50 { printf "%-50s\n",$0 }' in.txt
awk 'length <= 50 { printf "%-50s\n",$0 }' in.txt
Use a shell variable to pass the result from one script to another, using awk's -vargument parsing
使用 shell 变量将结果从一个脚本传递到另一个脚本，使用 awk 的-v参数解析
MAX=$(awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt)
MAX=$(awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt)
awk -v max=$MAX 'length <= max { printf "%-"max"sX\n",$0 }' in.txt
awk -v max=$MAX 'length <= max { printf "%-"max"sX\n",$0 }' in.txt
OR you could replace the hard-coded 50with shell $()command substitution to create this ugly one-line beast:
或者你可以50用 shell$()命令替换替换硬编码来创建这个丑陋的单行野兽：
awk -v max=$(awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt) 'length <= max { printf "%-"max"s\n",$0 }' in.txt
awk -v max=$(awk '{ if (length($0) > max){max = length($0)} } END { print max }' in.txt) 'length <= max { printf "%-"max"s\n",$0 }' in.txt
