Is it possible for a batch script to delete a single line in a txt file?
example:
my.txt contains the following:
ab
cd

is it possible to delete cd using batch?

also, what if i dont know what i want to delete.
example:
a random line.
i just need a batch file to delete the last or last 2 lines.

here's a vbscript. assuming the file is not in gigabyte sizes..
[code]
Dim objFSO,objFile,fileCount,allData,NumberOfLines
Const ForReading=1
Set objFSO=CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile("c:\test.txt", ForReading)
allData=Split(objFile.ReadAll,vbCrLf)
NumberOfLines = objFile.Line
objFile.Close
For fileCount = 0 to NumberOfLines - 2
WScript.Echo allData(fileCount)
Next
Set objFSO=Nothing
[/code]
on the command prompt, type cscript /nologo myscript.vbs > output

@ ghostdog
that did nothing except annoy the s--- out of me with over 250 text boxes because the file is huge! good try tho :P

My File Contains The Following:( X = RANDOM )

QXXXXXX
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
@XXXXXX

The file must delete "@XXXXXX", but leaving the rest untouched. I need user input however which is why i asked for batch. I need the user to be able to input the name of the file to be changed!

nope, it should not give you any textboxes.

This should work UNLESS the file has chars with 'special meaning' to the OS. Those are usually:

<>|%^&!

and maybe some others which don't come to mund.

::== delLAST.bat
:: del last line of txt :: NG if txt has <>|!% etc

@echo off > outfile
setlocal EnableDelayedExpansion

set /p FN=file name?
type !FN! | find /c /v "" > %temp%\#
set /p L=<%temp%\#
type !FN! | find /n /v "" > %temp%\##

for /f "tokens=1,* delims=[]" %%c in (%temp%\##) do (
if %%c equ !L! goto :eof
if '%%d'=='' ( echo. >> outfile
) else (
echo %%d >> outfile
)
)
:: DONE

=====================================
If at first you don't succeed, you're about average.

M2

Or more simply. [Simpler is better.] Same precaution applies.

::== del LAST line with FIND
@echo off > outfile
setlocal EnableDelayedExpansion

set /p FN=file name?

for /f "tokens=* delims= " %%c in (!FN!) do (
set str=%%c
)
find /v "!str!" < !FN! > outfile
:: DONE

=====================================
If at first you don't succeed, you're about average.

M2

Here's a Perl 1 liner option.

c:\>perl -MTie::File -e "tie @f,'Tie::File', 'my.txt'; pop @f; untie @f;"

=================================================

Or, if you want it in script form.

#!perl

use Tie::File;
tie @f,'Tie::File', $ARGV[0];
pop @f;
untie @f;

------------

executed as:

c:\>delete_last_line.pl my.txt

However, none of the proposed solutions meet all of the requested (or implied) requirements.

mechanix2go, you have outdone yourself! THANK YOU! 1 more thing tho. is it possible to check if there is an @ symbol on the last line before changing the file, to make sure it was not already changed? thanks again mechanix!

Not sure how you're defining already changed, but this will check to see if the last line contains an @.

::==

::== ::== del LAST line with FIND
:: del last line of txt :: NG if txt has <>|!% etc

@echo off > outfile
setlocal EnableDelayedExpansion

set /p FN=file name?

for /f "tokens=* delims= " %%c in (!FN!) do (
set str=%%c
)

echo !str! | find "@" > nul
if errorlevel 1 (echo there's no @
) else (
echo last line has an @
)

find /v "!str!" < !FN! > outfile
::==

=====================================
If at first you don't succeed, you're about average.

M2