Sstrhsrtj

I am using paste to merge three text files (which do not require sorting) into a single document with three columns.

paste a.txt b.txt c.txt

I'd like elements that the columns have in common to occupy the same row without sharing it with non-matching elements (which they currently do).
By the same token, unique elements should have their own rows. The elements in each column should preserve their original order.

Here's a simple example.

Input

1 1 1

2 2 2

3 4 4

5 5 5

1 1 2

3 3 3

Desired Output

1 1 1

2 2 2

3    

  4 4

5 5 5

1 1

    2

3 3 3

Here's a more complicated example.

Input

000 000 000

002 002 001

006 006 006

008 008 007

009 009 009

011 012 010

013 013 013

015 015 014

016 016 016

018 019 017

020 020 020

021 021 022

024 024 024

026 025 025

028 026 026

118 028 027

119 118 118

032 119 117

036 032 032

037 033 033

039 034 034

040 037 037

042 039 038

043 040 040

045 042 041

046 043 043

048 045 044

    046 046

    049 047

Desired Output

000 000 000

        001

002 002

006 006 006

        007

008 008 

009 009 009

        010

011        

    012 

013 013 013

        014

015 015 

016 016 016

        017

018     

    019 

020 020 020

021 021 

        022

024 024 024

    025 025

026 026 026

        027

028 028 

118 118 118

        117

119 119 

032 032 032

    033 033

    034 034

036     

037 037 037

        038

039 039 

040 040 040

        041

042 042 

043 043 043

        044

045 045 

046 046 046

        047

048     

    049

Ideally, I'd like to use tools that are built in to Linux/Unix. I'd also like the output to remain a single document with three columns, e.g., > whatever.csv.

The closest I've been able to get is to run sdiff on the original text files, but although that correctly aligns elements that the files share in common, it does not handle the differences as I would like.

BEGIN {

    # We assume the default input field separator (changeable with "-F")

    # Output will be tab delimited.

    OFS = "t"

}

{

    # The number of output records that this input record results in.

    k=0



    # "seen" records which new record a field should be part of.

    # There may be NF new records for each input record if all

    # fields are unique.

    delete seen



    # "a" holds all data for the new output records.

    # It's basically a 2-dimensional NFxNF matrix

    # encodod in a 1-dimensional array.

    delete a



    # Iterate over the fields

    for (i=1; i<=NF; ++i) {

        if (!seen[$i]) {

            # This data has not been seen before (in this input record),

            # assign it to the next output line.



            seen[$i] = ++k

        }



        # Assign the input field to the right spot

        a[(seen[$i]-1)*NF + i] = $i

    }



    # Save NF as this is reset by emptying $0 later.

    nf = NF



    # Create and output new lines

    for (j = 1; j<=k; ++j) {

        $0 = ""



        # Create new output record

        for (i = 1; i<=nf; ++i)

            $i = a[(j-1)*nf + i]



        # Output record

        print

    }

}

Testing on the given data:

$ awk -f script.awk file

1       1       1

2       2       2

3

        4       4

5       5       5

1       1

                2

3       3       3

Testing on other data:

$ cat file

a b c e

1 2 1 1

2 1 1 1

1 1 1 2

$ awk -f script.awk file

a

        b

                c

                        e

1               1       1

        2

2

        1       1       1

1       1       1

                        2

Here's a "brute force" solution in a shell script using paste and read.

#!/bin/sh



paste a.txt b.txt c.txt |

while read -r a b c; do

    if [ "$a" = "$b" ] && [ "$b" = "$c" ]; then

        printf '%st%st%sn' "$a" "$b" "$c"

    elif [ "$a" = "$b" ]; then

        printf '%st%sntt%sn' "$a" "$b" "$c"

    elif [ "$a" = "$c" ]; then

        printf '%stt%snt%sn' "$a" "$c" "$b"

    elif [ "$b" = "$c" ]; then

        printf '%snt%st%sn' "$a" "$b" "$c"

    else

        printf '%snt%sntt%sn' "$a" "$b" "$c"

    fi

done

There's probably a more elegant solution but I couldn't come up with a good one off the top of my head.

You could probably use awk instead if you prefer it -- I think the result would look very similar. (One advantage of using awk would be that it could potentially do the job of paste at the same time, if that's useful to you.)