Batch script to merge lines from two files into a third file

Question

Contents of file A1:

AA
VV
BB

Contents of file A2:

DD
EE
FF

I want to merge the

Answer 1

We can load the contents of the files into Batch variable arrays so each of its lines can be directly accessed in any way you wish:

@echo off
setlocal EnableDelayedExpansion

rem Load first file into A1 array:
set i=0
for /F "delims=" %%a in (A1.txt) do (
    set /A i+=1
    set A1[!i!]=%%a
)

rem Load second file into A2 array:
set i=0
for /F "delims=" %%a in (A2.txt) do (
    set /A i+=1
    set A2[!i!]=%%a
)

rem At this point, the number of lines is in %i% variable

rem Merge data from both files and create the third one:
for /L %%i in (1,1,%i%) do echo !A1[%%i]! is from !A2[%%i]!>> A3.txt

EDIT Alternative solution

There is another way to do it that don't use Batch variables so it can be used on files of any size, although it is slower. I borrowed the method used by Andy Morris in its solution: 1- Insert line numbers in both files, 2- Combine both files in one, 3- Sort the combined file, and 4- Merge groups of lines into one same line. The program below is basically Andy's one with several small modifications that made it faster (with a subtle error fixed).

@echo off
setlocal EnableDelayedExpansion

call :AddLineNumbers A1.txt A > Both.txt
call :AddLineNumbers A2.txt B >> Both.txt
sort Both.txt /O Sorted.txt
echo EOF: >> Sorted.txt
call :creatNewLines < Sorted.txt > Result.txt
goto :eof

:AddLineNumbers
findstr /n ^^ %1 > tem.tmp
for /f "tokens=1* delims=:" %%a in (tem.tmp) do (
    set /a lineNo=1000000+%%a
    echo !lineNo!%2:%%b
)
goto :eof

:creatNewLines
set /p lineA1=
for /f "tokens=1* delims=:" %%a in ("%lineA1%") do (
    if %%a == EOF goto :eof
    set /p dummy=%%b< nul
)
set /p lineA2=
for /f "tokens=1* delims=:" %%a in ("%lineA2%") do echo  is from %%b
goto creatNewLines

SORT command order lines based on its contents. Andy's original method may fail because after the line number the lines are ordered based on line contents, so the lines of each file may be misplaced. In this method an additional character (A or B) is added after the line number, so the lines of each file are always placed in the right place.

Answer 2

If your original data is in Data1.txt and Data2.txt this should do:

@echo off

    call :AddLineNumbers data1.txt Tem1.txt
    call :AddLineNumbers data2.txt Tem2.txt

    copy tem1.txt + tem2.txt tem3.txt 
    sort < tem3.txt > tem4.txt

    call :GetDataOut tem4.txt > tem5.txt

    set OddData=

    for /f %%a in (tem5.txt) do call :creatNewLines %%a

goto :eof



:AddLineNumbers

    find /v /n "xx!!xx" < %1 > tem.txt


    call :ProcessLines > %2


goto :eof

:ProcessLines

    for /f  "tokens=1,2 delims=[]"  %%a in (tem.txt) do call :EachLine %%a %%b 

goto :eof

:eachLine

    set LineNo=00000%1
    set data=%2 

    set LineNo=%LineNo:~-6%

    echo %LineNo% %data% 

goto :eof

:GetDataOut 
    for /f "tokens=2" %%a in (%1) do @echo %%a
goto :eof

:creatNewLines
    if "%oddData%"=="" (
        set oddData=%1
    ) else (
        echo %oddData% %1
        set oddData=
    )
goto :eof

Answer 3

If using linux, I would recommend using cut and paste (command line). See the man pages.

Alternatively, if you don't need the automation, you could use vim block mode cut and paste. Enter block mode visual mode with control-v.