How to remove carriage return and line feed characters from a text file using batch?

问题

I've a fixed width text file so it contains leading zeros and spaces and I need to remove carriage return and line feed characters from the file. Could you please let me know how can I do this using batch script?

Input:

ABCDEF  GHIJK0000ADS
ABCDEF  GHIJK0000ADS
ABCDEF  GHIJK0000ADS

Output:

ABCDEF  GHIJK0000ADSABCDEF  GHIJK0000ADSABCDEF  GHIJK0000ADS

Thanks, Niranjan

回答1:

There is no trivial pure batch solution if you have existing lines that may begin with spaces. It is possible to write such lines without newlines, but it takes a lot of code.

There are other issues that can further complicate a pure batch solution.

In general, Windows batch is poor choice for manipulating text files if you want a robust, general purpose solution,

That is why I wrote JREPL.BAT - a regular expression text processing utility. JREPL is pure script (hybrid batch/JScript) that runs natively on any Windows machine from XP onward. No 3rd party exe file is required.

Full documentation is accessed from the command console via jrepl /?, or jrepl /?? for paged output.

The solution is downright trivial with JREPL.

call jrepl "[\r\n]" "" /m /f "input.txt" /o "output.txt"

If you want to overwrite the original file, then

call jrepl "[\r\n]" "" /m /f "input.txt" /o -

This solution will work as long as your entire file can be read into memory by JScript. I believe the limit is close to 1 gigabyte.

回答2:

setlocal enabledelayedexpansion
set "line="
for /f "delims=" %%a in (filename.txt) do set "line=!line!%%a"
echo %line%

Read each line;accumulate. Relies on delayed expansion mode

回答3:

Here is an alternative method:

@echo off
for /F usebackq^ delims^=^ eol^= %%L in ("filename.txt") do (
    < nul set /P ="%%L"
)
echo/

Remove the echo/ command in case you do not want a final trailing line-break.

Advantages:

no accumulation of lines in a single variable, so files longer than ~ 8190 bytes are possible;

Disadvantages:

leading white-spaces get lost;
lines must not begin with =;

User dbenham mentioned non-trivial pure batch solutions in his answer that maintain leading white-spaces. I played around with the relying technique and come along with the following script to share:

@echo off
setlocal EnableExtensions DisableDelayedExpansion

rem // Define constants here:
set "_INFILE=filename.txt"         & rem // (input file; `%~1` is argument)
set "_TMPNAME=%TEMP%%~n0_%RANDOM%" & rem // (name of temporary files, no ext.)

rem // Build full names of temporary files:
set "$TMPFILE=%_TMPNAME%.tmp"
set "$SUBFILE=%_TMPNAME%.sub"

rem // Store SUB (EOF) character in variable:
> nul copy nul "%$SUBFILE%" /A
for /F "usebackq" %%F in ("%$SUBFILE%") do set "$SUBCHAR=%%F"

rem // Loop through lines of input file:
for /F usebackq^ delims^=^ eol^= %%L in ("%_INFILE%") do (
    rem // Append SUB char. to current line and write to temp. file:
    > "%$SUBFILE%" echo(%%L%$SUBCHAR%
    rem // Copy temp. file to another temp. file, omitting SUB char. plus next:
    > nul copy "%$SUBFILE%" /A "%$TMPFILE%" /B
    rem // Output content of second temporary file:
    type "%$TMPFILE%"
)

rem // Clean up temporary files:
del "%$SUBFILE%" "%$TMPFILE%"

endlocal
exit /B

Besides the fact that leading white-spaces are no longer lost, this approach does not result in an error when a line begins with an = sign.

来源：https://stackoverflow.com/questions/40480974/how-to-remove-carriage-return-and-line-feed-characters-from-a-text-file-using-ba

标签

windows

batch-file

command