逐行对齐列

Question

假设一个文件包含三列字符串。

> cat file
foo foo bar
bar baz
baz qux
qux

bash 中的什么命令（如果有）可用于将这些列逐行对齐？正确的输出如下所示：

> sought_command file
foo foo
bar     bar
baz baz
qux qux

Answer 1

使用 awk：

$ awk 'max<NF{max=NF} # Get max number of columns
    { #For every input line,
       for(i=1;i<=NF;i++){
           b[$i]++;   # Record all possible tokens, like foo, bar etc.
           a[i$i]++;  # Record their column indices
       }
    }

    END{
           for(i in b) #Get max length of all the tokens (for printing)
               if(c<length(i))
                   c=length(i); 

           for(i in b) # For each token,
           {
              for(j=1;j<=max;j++){ # For every column,
                  if(a[j i]) d = i; # Decide, if we want to print it, or left blank...
                  else d="";

                  printf "%-"(c+5)"s", d; # Print the token, or blank space
              }
              print ""; # Print newline after every tokens line.
           }
       }' test.input

foo     foo             
baz     baz             
qux     qux             
bar             bar

关于输入与输出数据的顺序：我认为没有任何输入标记顺序，因为下面的输入数据也应该给出类似的输出。

foo foo
bar
baz baz bar
qux qux

可以保持令牌首次出现的顺序。例如在上面（重新排序）的情况下，它将是 foo、bar、baz、qux。

$ awk 'max<NF{max=NF} # Get max number of columns
{ #For every input line,
    for(i=1;i<=NF;i++){

        if(!b[$i]++)
            token[j++]=$i;
        a[i$i]++;  # Record their column indices
    }
}

END{
    for(i in b) #Get max length of all the tokens (for printing)
        if(max_len<length(i))
            max_len=length(i); 

    PROCINFO["sorted_in"] = "@ind_num_asc";

    for(i in token) { # For each token,
        for(j=1;j<=max;j++){ # For every column,
            if(a[j token[i]]) d = token[i]; # Decide, if we want to print it, or left blank...
            else d="";

            printf "%-"(max_len+5)"s", d; # Print the token, or blank space
        }
        print ""; # Print newline after every tokens line.
    }
}' test.input.reordered

foo     foo             
bar             bar     
baz     baz             
qux     qux

逐行对齐列

Align columns against one another by row

string

bash

text-alignment