how to read a file from line x to line y (dos/win batch file)

I have a series of log files.

I parse these log files with findstr to determine the first instance of a string of text, then return the file name and the line lumber the match was found on as variables.

I then use findstr to parse the file the match was found in for another text string. I return the matching line number as a variable.

I now have the file, the starting and ending line numbers.

I need to return the block of text between my line numbers.

All output is redirected to a textfile represented by the variable casenotes

Here is my code:

:test
echo: >> %casenotes%
echo: test >> %casenotes%
for /f "tokens=1,2* delims=:" %%a in ('findstr /N /C:"Optimize ThreadPools" *_MAGT_*.txt') do set startline=%%b & set filefoundin=%%a & goto part2
:part2
for /f "tokens=1,2* delims=:" %%a in ('findstr /N /C:"After optimization" %filefoundin%') do set endline=%%a & goto part3
:part3
echo: >> %casenotes%
echo: filefound in: %filefoundin% >> %casenotes%
echo: startline is: %startline% >> %casenotes%
echo: endline is: %endline% >> %casenotes%
echo: >> %casenotes%
echo: now do something magic to read everything between lines %startline% and %endline% from %filefoundin% and redirect that output to %casenotes%

Any advice appreciated!

@Echo OFF

Set "File=Test.txt"
Set /A "Start_Line=3"
Set /A "End_Line=6"

For /F "Tokens=*" %%# In ('Type "%FILE%"') DO (
Call Set /A "Line+=1"
CMD /C "IF %%LINE%% GEQ %Start_Line% IF %%LINE%% LEQ %END_Line% (Echo %%#>>"Output.txt")"
)

Pause&Exit


> UPDATE

Another way with same accuracy

@Echo OFF

Set "File=Test.txt"
Set /A "Start_Line=3"
Set /A "End_Line=6"

For /F "Tokens=* delims=" %%# In ('Type "%FILE%"') DO (
Set /A "Line+=1"
CALL :READ_LINES "%%#"
)

:READ_LINES
(IF %LINE% GEQ %Start_Line% IF %LINE% LEQ %END_Line% (Echo %*>>"Output.txt") ELSE (GOTO:END)) & GOTO:EOF

:END
Pause&Exit




for any other type of text manipulation you can use my TEXTMAN subroutine the next time (Commentlines in spanish, sorry):

@Echo OFF

:: TEXT MANIPULATOR ROUTINE v0.1
:: by Elektro H@cker

USO:
:TEXTMAN [ACCIÓN] [LÍNEA] [ARCHIVO] [TEXTO (Opcional)]


REM ACCIONES:
REM
REM AL = ADD_LEFT * AÑADIR TEXTO AL PRINCIPIO DE UNA LÍNEA
REM AR = ADD_RIGHT * AÑADIR TEXTO AL FINAL DE UNA LÍNEA
REM E = ERASE * ELIMINAR UNA LÍNEA
REM I = INSERT * INSERTAR UNA LÍNEA (VACÍA O CON TEXTO)
REM RL = REPLACE_LINE * REEMPLAZAR UNA LÍNEA
REM RS = REPLACE_STRING * REEMPLAZAR PALABRAS DE UNA LÍNEA
REM RSA = REPLACE_STRING_ALL * REEMPLAZAR PALABRAS EN TODAS LAS LÍNEAS
REM C+ = CHARACTER_PLUS * ELIMINAR LOS PRIMEROS "X" CARACTERES EN TODAS LAS LÍNEAS
REM C- = CHARACTER_LESS * ELIMINAR LOS ÚLTIMOS "X" CARACTERES EN TODAS LAS LÍNEAS
REM L+ = LINE_PLUS * CORTAR LAS PRIMERAS "X" LÍNEAS
REM L- = LINE_LESS * CORTAR LAS ÚLTIMAS "X" LÍNEAS


REM EJEMPLOS DE USO:

:: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: ::
::
:: Elimina la línea 3
:: Call :TEXTMAN E 3 "Test.txt"
::
:: Añade una frase al principio de la línea 3
:: Call :TEXTMAN AL 3 "Test.txt" "Elektro H@cker"
::
:: Añade una frase al final de la línea 3
:: Call :TEXTMAN AR 3 "Test.txt" "Elektro H@cker"
::
:: Inserta una línea vacía en la línea 3
:: Call :TEXTMAN I 3 "Test.txt"
::
:: Inserta una línea con texto en la línea 3
:: Call :TEXTMAN I 3 "Test.txt" "Elektro H@cker"
::
:: Reemplaza la línea 3 por completo
:: Call :TEXTMAN RL 3 "Test.txt" "Elektro H@cker"
::
:: Reemplaza las palabras "Elektro" por "H@cker" en la línea 3
:: Call :TEXTMAN RS 3 "Test.txt" "Elektro" "H@cker"
::
:: Reemplaza las palabras "Elektro" por "H@cker" en todas las líneas
:: Call :TEXTMAN RSA "Test.txt" "Elektro" "H@cker"
::
:: Elimina los 3 primeros caracteres de todas las líneas
:: Call :TEXTMAN C+ 3 "Test.txt"
::
:: Elimina los 3 uúltimos caracteres de todas las líneas
:: Call :TEXTMAN C- 3 "Test.txt"
::
:: Elimina las 3 primeras líneas
:: Call :TEXTMAN L+ 3 "Test.txt"
::
:: Elimina las 3 últimas líneas
:: Call :TEXTMAN L- 3 "Test.txt"
::
:: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: :: ::

PAUSE&EXIT

:TEXTMAN
(SET /A "A=0", "LINE=0", "TOTAL_LINES=0") & (CALL :%~1 %* || (ECHO Parametro incorrecto & Exit /B 1)) & (GOTO:EOF)
:AL
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF NOT "%%LINE%%" EQU "%~2" (Echo %%@ >> "%~nx3.NEW") ELSE (Echo %~4%%@ >> "%~nx3.NEW")"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:AR
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF NOT "%%LINE%%" EQU "%~2" (Echo %%@ >> "%~nx3.NEW") ELSE (Echo %%@%~4 >> "%~nx3.NEW")"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:E
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF NOT "%%LINE%%" EQU "%~2" (Echo %%@ >> "%~nx3.NEW")"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:I
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF "%%LINE%%" EQU "%~2" (IF NOT "%~4" EQU "" (Echo %~4 >> "%~nx3.NEW") ELSE (Echo. >> "%~nx3.NEW"))" & Echo %%@ >> "%~nx3.NEW"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:RL
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF NOT "%%LINE%%" EQU "%~2" (Echo %%@ >> "%~nx3.NEW") ELSE (Echo %~4 >> "%~nx3.NEW")"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:RS
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" && (CMD /C "IF NOT "%%LINE%%" EQU "%~2" (Echo %%@ >> "%~nx3.NEW") ELSE (CALL SET "STRING=%%@" && CALL ECHO %%STRING:%~4=%~5%% >> "%~nx3.NEW")"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:RSA
(For /F "usebackq tokens=*" %%@ in ("%~2") DO (CALL SET "STRING=%%@" && (CALL ECHO %%STRING:%~3=%~4%% >> "%~2.NEW"))) && (CALL :RENAMER "%~2") & (GOTO:EOF)
:C+
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set "LINE=%%@" && (CALL ECHO %%LINE:~%~2%% >> "%~nx3.NEW"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:C-
(For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set "LINE=%%@" && (CALL ECHO %%LINE:~0,-%~2%% >> "%~nx3.NEW"))) && (CALL :RENAMER "%~3") & (GOTO:EOF)
:L+
(Call SET /A "A=%~2-1") && (Call TYPE "%~3" | @MORE +%%A%% > "%~nx3.NEW") && (CALL :RENAMER "%~3") & (GOTO:EOF)
:L-
(FOR /F %%X IN ('TYPE "%~3"') DO (CALL SET /A "TOTAL_LINES+=1")) & (CALL SET /A "TOTAL_LINES-=%~2-1") & (For /F "usebackq tokens=*" %%@ in ("%~3") DO (Call Set /A "LINE+=1" & Call echo " %%LINE%%!!| FINDSTR " %%TOTAL_LINES%% " && CALL :RENAMER "%~3" && GOTO:EOF || (Echo %%@ >> "%~nx3.NEW")))
:RENAMER
(REN "%~1" "%~nx1.BAK") & (MOVE /Y "%~nx1.BAK" "%TEMP%\" >NUL) & (REN "%~nx1.NEW" "%~nx1") & (GOTO:EOF)

try this:
@echo off




set file_to_read=read.txt
set /a start_line=1
set /a end_line=6
set outfile=outfile
set counter=1

break > %outfile%
setlocal ENABLEDELAYEDEXPANSION


for /f "delims=*" %%A in (%file_to_read%) do (
if !counter! GEQ !start_line! (
echo %%A
echo %%A >> !outfile!
)
set /A counter=!counter!+1

if !counter! GEQ !end_line! (
goto :endLoop
)
)
:endLoop
This will no count empty lines.

The Batch file below is the fastest way to do that, specially if the file is large.

echo: read everything between lines %startline% and %endline% from %filefoundin% and redirect that output to %casenotes%

setlocal EnableDelayedExpansion
set skip=
set /A skiplines=startline-1, numlines=endline-startline+1
if %skiplines% gtr 0 set skip=skip=%skiplines%
(for /F "%skip% delims=" %%a in (%filefoundin%) do (
echo %%a
set /A numlines-=1
if !numlines! equ 0 goto part4
)) > %casenotes%
:part4

If the file contain exclamation-marks, a small modification is needed to avoid the Delayed Expansion. Please, ask for it if you need it.

Please be aware that this solution ignore empty lines in the file. This detail may also be solved, if needed.

Antonio