batch script to print previous and next lines of search string in a text file

Question

I have a batch script which will print the entire line of search string into a text file.

for %%i in (log.txt) do (
FINDSTR /G:pattern.txt %%i >> outpu         


        

Answer 1

try this:

for /f "delims=:" %%a in ('findstr /in "error" log.txt') do set /a found=%%a
if not defined found (echo "error" not found&goto:eof)
set /a line1=found-1
set /a line2=found+1
for /f "tokens=1*delims=:" %%a in ('findstr /in "^" log.txt') do (
    if %%a==%line1% >>output.txt echo(%%b
    if %%a==%line2% >>output.txt echo(%%b
)

Answer 2

@echo off
setlocal EnableDelayedExpansion
rem Assemble the list of line numbers
set numbers=
for /F "delims=:" %%a in ('findstr /I /N /C:"error occurred" log.txt') do (
   set /A before=%%a-1, after=%%a+1
   set "numbers=!numbers!!before!: !after!: "
)
rem Search for the lines
(for /F "tokens=1* delims=:" %%a in ('findstr /N "^" log.txt ^| findstr /B "%numbers%"') do echo %%b) > output.txt

Answer 3

This uses a helper batch file called findrepl.bat from - http://www.dostips.com/forum/viewtopic.php?f=3&t=4697

@echo off
set "var=searchterm"
type "file.txt"|findrepl "%var%" /o:-1:+1 |find /v "%var%"