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bash 中的复杂文本对齐

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bash 中的复杂文本对齐

鉴于此输入：

# Lines starting with # stay the same
# Empty lines stay the same
# only lines with comments should change

ls  # show all major directories
              # and other things

cd      # The cd command - change directory  
            # will allow the user to change between file directories

touch             # The touch command, the make file command 
                # allows users to make files using the Linux CLI #  example, cd ~

bar foo baz # foo foo foo

我需要保留以 开头的行#和不包含任何注释的行，但将所有其他注释对齐在同一列上。

期望的输出：

# Lines starting with # stay the same
# Empty lines stay the same
# Only lines with # in middle should change and be aligned

ls              # show all major directories
                # and other things

cd              # The cd command - change directory  
                # will allow the user to change between file directories

touch           # The touch command, the make file command 
                # allows users to make files using the Linux CLI #  exmaple, cd ~

bar foo baz     # foo foo foo

到目前为止我所拥有的：

# Building an array out of input
 while IFS=$'\n' read -r; do 
    lines+=("$REPLY") 
 done 

# Looping through array and selecting elemnts that need change 
for i in "${lines[@]}"
  do
    if  [[ ${i:0:1} == ';' || $i != *";"* ]];
      then
        echo "DOESNT CHANGE: #### $i"
    else 
        echo "HAS TO CHANGE: #### $i"
        array+=( "${i%%";"*}" );
        array2+=("${i##";"}")
    fi
done

# Trying to find the longest line to decide how much space I need to add for each element
max = ${array[0]}

for n in "${array[@]}" ; do
    ((${#n} > max)) && max=${#n}
    echo  "Length:" ${#n} ${n}
done

#Longest line
echo $max

# Loop for populating array 
for j in "${!array2[@]}" ; do
    echo "${array2[j]} " | sed -e "s/;/$(echo "-%20s ;") /g" 
done

我感觉我做得太多了。我认为应该有一种更简单的方法来解决这个问题。

答案1

如果您的所有命令和参数都不包含#, 和另一个字符（例如字节 1 给出的 ASCII 字符），您可以插入该其他字符作为额外的分隔符并用于column对齐注释（请参阅这个答案）。所以，像这样：

$ sed $'s/#/\001#/' input-file | column -ets $'\001'
# Lines starting with # stay the same
# Empty lines stay the same
# only lines with comments should change

ls                                        # show all major directories
                                          # and other things

cd                                        # The cd command - change directory
                                          # will allow the user to change between file directories

touch                                     # The touch command, the make file command
                                          # allows users to make files using the Linux CLI #  example, cd ~

bar foo baz                               # foo foo foo

如果您column不支持-e避免消除空行，您可以向空行添加一些内容（例如，空格或上面使用的分隔符）：

$ sed $'s/#/\001#/;s/^$/\001/' input-file | column -ts $'\001'
# Lines starting with # stay the same
# Empty lines stay the same
# only lines with comments should change

ls                                        # show all major directories
                                          # and other things

cd                                        # The cd command - change directory
                                          # will allow the user to change between file directories

touch                                     # The touch command, the make file command
                                          # allows users to make files using the Linux CLI #  example, cd ~

bar foo baz                               # foo foo foo

答案2

单独使用 shell 进行文本处理有点尴尬，并且可能容易出错（请参阅“为什么使用 shell 循环处理文本被认为是不好的做法？")。通常最好使用其他编程语言来完成此类任务。

perl -ne 'if (/^([^#]+?)\s*#(.*)$/) { printf("%-16s#%s\n", $1, $2) } else { print }' file

这使用 Perl 捕获 前面的位#（丢弃最后一个字和 之间的空格#）和后面的位。如果匹配成功，它会为文本分配 16 个字符位置并打印格式化文本和注释。如果匹配不成功（因为该行为空或以 开头#），则不加修改地打印该行。

# Lines starting with # stay the same
# Empty lines stay the same
# only lines with comments should change

ls              # show all major directories
                # and other things

cd              # The cd command - change directory
                # will allow the user to change between file directories

touch           # The touch command, the make file command
                # allows users to make files using the Linux CLI #  example, cd ~

bar foo baz     # foo foo foo

答案3

这是一个可以执行您想要的操作的 Python 脚本：

#!/usr/bin/env python
# -*- encoding: ascii -*-
"""align.py"""

import re
import sys

# Read the data from the file into a list
lines = []
with open(sys.argv[1], 'r') as textfile:
    lines = textfile.readlines()

# Iterate through the data once to get the maximum indentation
max_indentation = 0
comment_block = False
for line in lines:

    # Check for the end of a comment block
    if comment_block:
        if not re.match(r'^\s*#.*$', line):
            comment_block = False

    # Check for the beginning of a comment block
    else:
        if re.match(r'^[^#]*[^ #].*#.*$', line):
            comment_block = True
            indentation = line.index('#')
            max_indentation = max(max_indentation, indentation)

# Iterate through the data a second time and output the reformatted text
comment_block = False
for line in lines:
    if comment_block:
        if re.match(r'^\s*#.*$', line):
            line = ' ' * max_indentation + line.lstrip()
        else:
            comment_block = False
    else:
        if re.match(r'^[^#]*[^ #].*#.*$', line):
            pre, sep, suf = line.partition('#')
            line = pre.ljust(max_indentation) + sep + suf
            comment_block = True

    sys.stdout.write(line)

像这样运行它：

python align.py input.txt

它产生以下输出：

# Lines starting with # stay the same
# Empty lines stay the same
# only lines with comments should change

ls                # show all major directories
                  # and other things

cd                # The cd command - change directory  
                  # will allow the user to change between file directories

touch             # The touch command, the make file command 
                  # allows users to make files using the Linux CLI #  example, cd ~

bar foo baz       # foo foo foo

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