China DOS Union

Okay, but the p is making me dizzy. If there's another VBS one, that would be great.

I don't know how efficient it is to handle files with N W lines

Originally posted by vkill at 2007-3-18 18:00:
I don't know how efficient it is to handle files with N W lines

　　Brother, I haven't thought about this problem. I estimate that this small function can only handle some small text, and it won't work for large ones.

I can't think of a way to use the moderator's file to read only the first line for the time being, so I擅自 changed it and swapped the positions of parameter 2 and parameter 3. Using ReadLine a.txt 1 can read the first line, and using ReadLine a.txt 1 1 can read the second line. Thank you, moderator. This file is very useful, and I hope the moderator will forgive me.

@echo off&SetLocal ENABLEDELAYEDEXPANSION

if "%1"=="" (goto --help) else (set file=%~s1)

if "%3"=="" (set first="delims=: tokens=1*") else (set first="skip=%3 delims=: tokens=1*")

if "%2"=="" (

        for /f %first% %%a in ('findstr /n .* %file%') do echo/%%b

        goto :EOF

)

set last=%2

set loop=0

for /f %first% %%a in ('findstr/n .* %file%') do (

        if not defined lxmxn (echo/%%b&set /a loop+=1) else (goto :EOF)

        if "!loop!"=="%last%" set lxmxn=Nothing

)

GOTO :EOF

:--help

echo/======================================

echo/This program segment needs to be run with parameters

echo/&echo/Usage:&echo/Call ReadLine ^<file name^> ^<number of lines to read^> ^<number of lines to skip^>

echo/&echo/For example: call ReadLine aa.txt 5 7, which will skip the first 7 lines of the aa.txt file and read the following 5 lines of characters

echo/&echo/If ^<number of lines to skip^> is not specified, it will be read from the first line of the file

echo/======================================

goto :eof

[ Last edited by tclgb on 2007-7-9 at 01:31 PM ]

Skipping zero lines is just to read the first line, right?

They are all experts. ......

Re:59fei

Brother 59fei, you can run the original file's ReadLine a.txt 0 1 and see what prompts come up. It will prompt an error on my side.

I've learned quite a lot of knowledge again

Your input contains some incomplete content. The full correct code should be:

@echo off
setlocal EnableDelayedExpansion
set loop=0
set /a skipline=%2-1
for /f "tokens=1 skip=%skipline% delims=" %%a in (%1) do (
set /a loop=!loop!+1
if "!loop!" leq "%3" (echo %%a) else goto :eof
)
goto :eof

Translated as:

@echo off
setlocal EnableDelayedExpansion
set loop=0
set /a skipline=%2-1
for /f "tokens=1 skip=%skipline% delims=" %%a in (%1) do (
set /a loop=!loop!+1
if "!loop!" leq "%3" (echo %%a) else goto :eof
)
goto :eof

Test the versions of the great gods on each floor above. It seems that it's always a bit uncomfortable to use. I擅自 made the following changes. For personal use, it currently meets all situations. Please give more advice.

:ReadLine <DataFileName> <skipline> <readline>
:: DataFileName File to be read in
:: skipline Number of lines to skip. If empty or not a valid number, it defaults to 0
:: readline Number of lines to read. If empty or not a valid number, it defaults to 0. 0 means all remaining
@echo off&SetLocal ENABLEDELAYEDEXPANSION
if "%1"=="" goto :--help
set /a loop=0
set /a skipline=%~2+0
set /a readline=%~3+0
if %skipline% lss 1 (
set "for_var=usebackq tokens=1 delims="
) else (
set "for_var=usebackq tokens=1 skip=%skipline% delims="
)
if %readline% lss 1 (
set /a step=0
set /a readline=1
) else (
set /a step=1
)
for /f "%for_var%" %%a in ("%~f1") do (
set /a loop+=step
if !loop! leq %readline% (echo %%a) else goto :eof
)
goto :eof
:--help
echo/======================================
echo / This program segment needs parameters to run normally
echo/&echo/Usage:&echo/Call ReadLine ^<File name^> ^<Number of lines to skip^> ^<Number of lines to read^>
echo/&echo / For example: call ReadLine aa.txt 5 7, which will skip the first 5 lines of the aa.txt file and read the next 7 lines of characters
echo/&echo / If ^<Number of lines to skip^> is not specified, it will be read from the first line of the file
echo/&echo / When specifying ^<Number of lines to read^>, you must specify ^<Number of lines to skip^>
echo/======================================
goto :eof