skip header line and replace string in text file in batch script

Question

@echo off     
setlocal enableextensions disabledelayedexpansion    
for /r %f in (xis_a*) do  More +1 %~nxf >> No_header_%~nxf    
set "search=:20:"

    set "replace={:20:"
    for /f "delims=" %%i in ('type (No_header_*.txt) ^& break ^> (No_header_*.txt) ') do (
        set "line=%%i"
        setlocal enabledelayedexpansion
        set "line=!line:%search%=%replace%!"
        >>No_header_*.txt echo(!line!
        endlocal
    )

am trying to skip the header line in a text file and replace :20: with {:20:. i have written and have achieved almost.. please try to help me am totally new to this

Answer 1

@ECHO OFF
SETLOCAL
SET "sourcedir=U:\sourcedir"
SET "destdir=U:\destdir"
set "search=:20:"
set "replace={:20:"

for /r "%sourcedir%" %%f in (xis_a*) do (
 REM DEL "%destdir%\No_header_%%~nf.txt" >NUL 2>nul
 for /f "usebackqskip=1delims=" %%i in ("%%f") do (
  set "line=%%i"
  setlocal enabledelayedexpansion
  set "line=!line:%search%=%replace%!"
  >>"%destdir%\No_header_%%~nf.txt" echo(!line!
  ENDLOCAL
 )
)

GOTO :EOF

This should solve the problem.

In your code, the initial setlocal is establishing the default condition, so I omitted it.

You have %f in your 'for /r - the % before the metavariable f needs to be doubled.

The more ceremony isn't required - for /f has a skip option which will allow the first n lines to be skipped.

So - all that is required is to get the list of files generated by the for...%%f... loop and with each, process each individual file, skipping the first line. Quoting the filename appearing in %%f is simply a safety-measure to allow for filenames containing separators, but this means that usebackq needs to be invoked to tell for /f that the list given is not a literal string (which it will assume for a "quoted string,") but a filename.

Then, since %%f is in-context for the %%i loop, you can select the target filename by using %%~nf . I'm not sure whether you want ~nf or ~nxf (adding a second .txt extension) so I elected to use ~n alone. Note that your use of * is doomed - that means "all files matching" - probably not quite what you want, and cmd will get very confused.

I've aded a remmed-out del command to allow the destination file to be deleted - just remove the rem if required, otherwise the data will be appended to any exiating file.

I use my u: drive for testing, and have left my source and destination names in place. No doubt you would need to change those to suit your system.