DosTips.com

@echo off

for /F "usebackq delims= " %%C in (`copy /z "%~f0" nul`) do set "$CR=%%C"

set "PROMPT=$LPHASE3$G "
echo on
set ^"var1=BEGIN-%===%3>NUL END"
set ^"var2=BEGIN-%$CR%3>NUL END"

set var

Output wrote:$ ./remoteExec.sh "phase_error_CR.bat"

<PHASE3> set "var1=BEGIN-3 END" 1>NUL

<PHASE3> set "var2=BEGIN- END" 3>NUL

<PHASE3> set var
var1=BEGIN-3 END
var2=BEGIN- END

But now, how is this possible

jeb wrote: But now, how is this possible
Phase 1.5 removes the CR
Phase 2 handles redirects, it shouldn't know that there was a CR at all

penpen wrote: What proof do we have that removing <CR> characters is performed in an own phase and not handled as a special character in Phase 2, where tokenization might cause that above difference?

dbenham wrote: ↑

29 Jan 2020 22:14

Now if redirection is discovered, the parser could look backward in the original phase 1 output buffer to determine if the prior character is a digit (valid handle identifier). If it is a digit, then it may represent a file handle, in which case it must look at the character before that. If it sees a CR, ignore it and keep looking at the prior character until it is not CR or there are no more characters. Now if that prior character is an appropriate stop character, then the digit is indeed a file handle that must be removed from the prior parsed token and moved to the redirection token. If the prior character is ^ then it could be an escape or literal; either way it doesn't matter as long as ^ is not considered a stop character - the digit is a literal and not a file handle.

echo #1: 3 is ... part of redirect ^^^^^^%$CR%3>&2 END
echo #2: 3 is not part of redirect ^^^^^^^%$CR%3>&2 END

echo #3: 3 is not part of redirect -^
3>&2 END

echo #4: 3 is not part of redirect -^
%$CR%3>&2 END

echo #5: 3 is ... part of redirect 4>NUL -^
%$CR%3>&2 END

REM -----------^
#1 Line is part of the comment

REM -%$CR%-----^
#2 Line is part of the comment

REM - ---------^
#3 Line is NOT part of the comment

jeb wrote: ↑

13 Feb 2014 03:22

To avoid this you can simply use the obvious dummy redirect trick.

Code: Select all

echo Word1<nul ^
%= REM this is a comment line%^
Word2

jeb wrote: ↑

19 Feb 2014 12:30

First a sample

Code: Select all

echo Hello <nul the^
only^
world

Output wrote:Hello world

1                    2        3                                    4
^                    ^        ^                                    ^
((^|[\s=,;"()&|])\d)?(>>?|<)(&\d|[\s=,;]*(\^&\d|FilePath|device))(([\s=,;]+(\^[\s=,;]|[^\s=,;])+)\^\n)*

1. Optional file handle to redirect or define:
   
   • Must be a single digit.
   • There must not be a character before the digit (beginning of "line")
     or
     The preceding character must be whitespace , ; = ( ) " & or |
   • CR functions as a temporary whitespace in this step, even though it is subsequently removed.
     If before the digit, then it may allow the digit to be a file handle.
     If after the digit, then it may prevent the digit from being a file handle.
   • The digit must not be escaped (I did not explicitly put this in the regex)
     An intervening temporary CR whitespace does not prevent a caret from escaping the digit.
2. Redirection operator:
   • < or > or >>
3. Redirection destination
   • File Handle:
     • & followed by a digit
       All subsequent characters are preserved
     • or Optional unescaped token delimiters followed by ^& followed by a digit.
       Subsequent characters are ignored until the next unescaped/unquoted token delimiter
       meaning they are functionally stripped, but still appear in the phase 3 echo output
   • or File Path:
     • optional unescaped token delimiters followed by "normal" file specification (may include escaped/quoted token delimiters)
   • or Device:
     • optional unescaped token delimiters followed by "normal" device specification (I'm a bit fuzzy on these rules)
4. Strip token delimiters followed by token if it ends with line continuation (recursive)
   • If after the redirection target there exists one or more unescaped token delimiters,
     followed by a single token (may include escaped/quoted token delimiters), followed by line continuation,
     then strip everything after the redirection destination before appending the next line.
     The first character of the next line is not escaped (unlike normal line continuation)
   • Repeat until no more lines or multiple tokens after destination.
   • I believe this is the same rule as is used for the REM parser.

dbenham wrote: ↑

31 Jan 2020 14:03

Now you (penpen) have discovered another complication with this redirection line continuation process.

@echo off
set "prompt=#" 
cls
echo on

echo >con ^<nul cmdToken and some params
echo >con  <nul cmdToken and some params

echo,>con,<!!!(((aaaZZZ)))---[[[]]]{{{}}}'''+++```~~~,^<nul,cmdToken,and,some,params
echo,>con,<!!!(((aaaZZZ)))---[[[]]]{{{}}}'''+++```~~~,<nul,cmdToken,and,some,params

@echo off
set "prompt="
goto :eof

echo abc <this <that <nul

echo ^<This doesn't produce the issue.