File handling in Batch programming?

Question

I have a text file that has a number in every new line and all are in ascending order.

Contents are like :

1
13
25
37
49
97
109
121

I want to extract only those numbers who have difference greater than 12, with the previous number. I wish to use batch program for this....

How can I do that ?

Answer 1

I would have liked to see you make an attempt but anyway I had a go and this is the closest I could get

c:\temp>type test.txt
1 line 1
10 line 1a
13 line 2
25 line 3
22 line 3a
37 line 4
49 line 5
97 line 6
109 line 7
121 line 8

c:\temp>test.bat
25 line 3
37 line 4
49 line 5
97 line 6
109 line 7
121 line 8

c:\temp>

using this code in test.bat:

@echo off

SETLOCAL ENABLEDELAYEDEXPANSION

set /a cur="0"
for /f "tokens=1,* delims= " %%a in ('type test.txt') do (

  set line=%%a %%b   

  set /a num="%%a"
  set /a dif="!num!-!cur!"

  if !dif! geq 12 @echo !line!

  set /a cur="%%a"
)