windowsbatch-filecmd

How to write a line feed <LF> to a file?

The following Windows batch file sets the contents of the out.txt file to two ASCII characters, namely: X and <LF> (0x58 and 0x0A ).

@echo off
SETLOCAL
SET LF=^


set /p=X^%LF%%LF%<nul>out.txt

Note the mandatory empty lines after the statement SET LF=^

How to change this batch file so it sets the contents of the out.txt file to only one ASCII character, namely the: 0x0A (<LF>) character?

RESTRICTIONS:
This question relates only to the internal commands implemented in cmd.exe (not PowerShell !) and only to the native external commands installed in standard Windows installations >= Windows 7 x64 (no 3rd party tools, no debug.exe). This question is not about how to accomplish this goal with scripting languages such as VBscript or JSscript nor how to write a program in C, C#, Python or any language other than the Windows batch language (if you can call it that). Assume a restricted user without administrative rights, so neither fsutil nor certutil work.

Solution

  • A single line feed can be written to a file by the use of the prompt command

    @echo off
setlocal

(set prompt=^
%= Don't delete this line =%
)

cmd /d /k < nul > single-linefeed.txt