Question: To delete all lines of a txt file that begins with a space (including empty lines), I write 

```
    findstr /v /b /c:" " <%1>result.out.

```

Indeed, result.out file get answer for me if there is no longer both space at beginning of every line and empty line.

What I have done still leaving lines header empty, it also preserves blank lines what i want to give up. Finally, the result.out output must have consecutive lines always containing a text at begining of each line.

Please someone could tell me what it is faulty and how to fix that?
Thanks.

Answer: 
If you want to include `Tab` characters as part of the whitespace you want to check, you have to use a batch script. The `cmd` console simply makes an annoyed sound at you if you try to `Tab` or paste a `Tab` character into the console. But `cmd` interprets `Tab` in a `.bat` file no problem.

Put this into a batch file and run it, replacing `Space` and `Tab` with an actual space and tab.

> 
> `findstr /r /v /c:"^[``Space``Tab``]" /c:"^$" "%~1" >result.out`
> 
> 
> 

The first `/c:` checks for whitespace at the beginning of a line. The second `/c:` checks for blank lines. Both are omitted with the `/v` switch.
```
@ECHO OFF
SETLOCAL
CALL CMD /c EXIT 26
(
FOR /f "eol=%=ExitCodeAscii% delims=" %%i IN ('findstr /v /b /c:" " ^<%1') DO ECHO %%i
)>result.out

```

Should remove blank lines.

The `FOR` reads each line of the file that appears after FINDSTR has removed all of the lines with trailing spaces. Any empty lies are discarded, and the entire line is applied to %%i because there are no delimiters.

By setting the end-of-line character to control-Z, there are effectively no end-of-lines either, so all non-empty lines are `ECHO`ed