FOR issues

[Raistlin]

1. FOR can't be used in @EXEC. Example:

   echo %@exec[@for ^%A in (123) echo %A] > nul

   returns "ECHO IS OFF".
2. SWITCH works incorrectly from inside FOR loop: executing

   for %A in (123) (
    switch a
    case a
     echos aaa
    case f
     echo fff
    endswitch
   )

   returns "aaafff".

 

[Raistlin]

3. It seems that RETURN is not allowed in nested FOR loops: executing

gosub aaa
echo %bbb
quit
:aaa
for %A in (123) (
 for %B in (345) (
  return
 )
 set bbb=ccc
)

displays "ccc".

 

[Charles Dye]

FOR can't be used in @EXEC. Example:

echo %@exec[@for ^%A in (123) echo %A] > nul

returns "ECHO IS OFF".

I believe you need to double your percent signs here:

echo. %@exec[@for %%A in ( 123 ) echo %%A]

(The period after ECHO is a rather nasty way of preventing the "ECHO is OFF" message.)

SWITCH works incorrectly from inside FOR loop: executing

for %A in (123) (
 switch a
 case a
  echos aaa
 case f
  echo fff
 endswitch
)

returns "aaafff".

SWITCH is inherently a multiline construct, and FOR is inherently single-line. Use DO instead.

 

[vefatica]

On Fri, 13 Jun 2008 16:29:59 -0500, you wrote:

>echo %@exec[@for ^%A in (123) echo %A] > nul
>---------
>returns "ECHO IS OFF".

v:\> echo %@exec[for %%A in (123) echo %%A]
123
0

v:\> echo %@exec[@for %%A in (123) echo %%A]
123
ECHO is OFF

as expected.

 

[Raistlin]

Charles Dye

I believe you need to double your percent signs here

Yeah, I'm wondering why I haven't tried this myself :)

SWITCH is inherently a multiline construct, and FOR is inherently single-line. Use DO instead.

Well IFF is another multiline construct, but it works inside FOR loop.

Anyway, I believe such things should be illustrated in Help.

 

[Steve Fabian]

Raistlin wrote:
| *Charles Dye*
| ---Quote---
| I believe you need to double your percent signs here
| ---End Quote---
| Yeah, I'm wondering why I haven't tried this myself :)
|
| ---Quote---
| SWITCH is inherently a multiline construct, and FOR is inherently
| single-line. Use DO instead. ---End Quote---
| Well IFF is another multiline construct, but it works inside FOR loop.

Technically, DO and SWITCH are multiline commands; IFF is a multiple
command.

|
| Anyway, I believe such things should be illustrated in Help.

Agreed. Some elements are. Impossible to illustrate all possible variations.
SWITCH is documented to perform its actions "in a batch file". The existence
of limitations in using a command group in the DO clause of FOR is also
documented.
--
Steve