Question

I want to store the output of text file into a variable, so I can pass the whole file as parameter.

I am using Windows 2003 Server.

The text files have multiple lines like:

10.20.210.100 fish
10.20.210.101 rock

I was using:

Set /P var=<file.txt

It reads only the first line of the file.

I tried with FOR loop also but it assigned only the last line to the variable.

Answer 1

There is no simple way to get the complete content of a file into one variable.
A variable has a limit of ~8100 length.
And it is complicated to get CR/LF into a variable

But with a FOR-loop you can get each single line.

Try a look at batch script read line by line

EDIT:
To get each line in a single variable you can use this

@echo off
SETLOCAL EnableDelayedExpansion
set n=0
for /f "delims=" %%a IN (example.txt) do (
  set /a n+=1
  set "line[!n!]=%%a"
  echo line[!n!] is '%%a'
)
set line

or to get all in only one variable (without CR/LF)

@echo off
SETLOCAL EnableDelayedExpansion
set "line="
for /f "delims=" %%a IN (example.txt) do (
  set "line=!line! %%a"
)
echo !line!