Is it possible to use a piped stdin stream inside a batch file?
I want to be able to redirect the output of one command into my batch file process.bat
list so:
C:\>someOtherProgram.exe | process.bat
My first attempt looked like:
echo OFF
setlocal
:again
set /p inputLine=""
echo.%inputLine%
if not (%inputLine%)==() goto again
endlocal
:End
When I test it with type testFile.txt | process.bat
it prints out the first line repeatedly.
Is there another way?
set /p
doesn't work with pipes, it takes one (randomly) line from the input.
But you can use more
inside of an for-loop.
@echo off
setlocal
for /F "tokens=*" %%a in ('more') do (
echo #%%a
)
But this fails with lines beginning with a semicolon (as the FOR-LOOP-standard of eol is ;
).
And it can't read empty lines.
But with findstr you can solve this too, it prefix each line with the linenumber, so you never get empty lines.
And then the prefix is removed to the first colon.
@echo off
setlocal DisableDelayedExpansion
for /F "tokens=*" %%a in ('findstr /n $') do (
set "line=%%a"
setlocal EnableDelayedExpansion
set "line=!line:*:=!"
echo(!line!
endlocal
)
Alternatively, on some environments (like WinRE) that don't include findstr
, an alternative with find.exe
might suffice. find
will accept a null search string ""
, and allows search inversion. This would allow something like this:
@echo off
setlocal DisableDelayedExpansion
for /F "tokens=*" %%a in ('find /v ""') do (
...