Batch file FOR /f tokens

Question

Can anyone please explain exactly how the following code works, line by line. I'm really lost. I've been trying to learn how to use the FOR command but I don't understand this.

@echo off

for /f "tokens=* delims= " %%f in (myfile) do (
  set line=%%f
  call :processToken
  )
  goto :eof

:processToken

  for /f "tokens=1* delims=/" %%a in ("%line%") do (
  echo Got one token: %%a
  set line=%%b
  )
  if not "%line%" == "" goto :processToken
  goto :eof

Answer 1

for /f "tokens=* delims= " %%f in (myfile) do

This reads a file line-by-line, removing leading spaces (thanks, jeb).

set line=%%f

sets then the line variable to the line just read and

call :procesToken

calls a subroutine that does something with the line

:processToken

is the start of the subroutine mentioned above.

for /f "tokens=1* delims=/" %%a in ("%line%") do

will then split the line at /, but stopping tokenization after the first token.

echo Got one token: %%a

will output that first token and

set line=%%b

will set the line variable to the rest of the line.

if not "%line%" == "" goto :processToken

And if line isn't yet empty (i.e. all tokens processed), it returns to the start, continuing with the rest of the line.