Batch file to add characters to beginning and end of each line in txt file

Question

I have a text file, I was wondering anyone have a batch file to add \" to the beninning and \", at the end of each line in a text file?

For example I have

Answer 1

The script uses a FOR loop count the # of lines, and FOR /L along with SET /P to read the file line-by-line:

@echo off
SETLOCAL EnableDelayedExpansion

::Initialize SUB character (0x1A)
>nul copy nul sub.tmp /a
for /F %%S in (sub.tmp) do set "sub=%%S" SUB CHARACTER

::Variables
;set "lines=-1" Exclude LAST line
set "in="
set "out=text.txt"

::Count lines
FOR /F tokens^=*^ delims^=^ eol^= %%L in (
'2^>nul findstr /N "^" "%in%"'
) do set /a "lines+=1"

::Read file using SET /P
>newline.tmp <"!in!" (
  for /L %%a in (1 1 %lines%) do (
    set "x=" For EMPTY lines
    set /p "x="
    echo("!x!",
  )
    ;set "x="
    ;echo("!x!",!sub!
)

::Trim trailing newline appended by ECHO
;copy newline.tmp /a "!out!" /b
;del sub.tmp newline.tmp

The foolproof way of counting the number of lines is explained in this answer.
Takes advantage of the SUB character (0x1A) to trim trailing newlines, discussed here on DosTips. If you don't want to trim them, just comment out the lines that start with ;.