how to read line in text file and return it by function

[sincos2007]

In my situation, command string in function used to make return value from function is necessary.

Code: Select all

:test2
setlocal EnableDelayedExpansion

set "_ret="
for /f "delims=" %%i in (temp.txt) do (
	setlocal DisableDelayedExpansion
	rem echo %%i
	set "_ret=set %~1=%%i"
	endlocal
)

(
   endlocal
   %_ret%
)
goto :eof

Code: Select all

set "var1="
call :test2 var1
echo %var1%

content of temp.txt, only one line in my case

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) el

[aGerman]

1) You still do it the wrong way. You mess up EnableDelayedExpansion and DisableDelayedExpansion
2) Please provide an exeample that shows why you even need to toggle these subenvironments.

If the only reason for your subroutine is that you want to read the first line of a file then you don't even need it.

Code: Select all

set "var1=" & <"temp.txt" set /p "var1="

Steffen

[sincos2007]

Hi Steffen,

Look following code:

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:test6
setlocal EnableDelayedExpansion

set "lines_cnt=2"
set "in_file=temp.txt"
set "line="
set /a "n=0"

<"!in_file!" (
	for /l %%j in (1 1 !lines_cnt!) do (
		set "line=" &set /p "line="
		if defined _ret (
			set "_ret=!_ret!^&"
		)
		set "_ret=!_ret!set %~1[!n!]=!line!
		set /a "n+=1"
	)
)

rem debug
echo debug 1
echo !_ret!

(
	endlocal
	%_ret%
)
goto :eof

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set "var1="
call :test6 var1
echo %var1[0]%
echo %var1[1]%

content of temp.txt

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) el
kkk ww

When I run this batch, I get error information.

If I change content of temp.txt to

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el
kkk ww

It runs well.

[aGerman]

No need to toggle delayed expansion here.

Code: Select all

@echo off
setlocal DisableDelayedExpansion

call :test6 foo
set "line_count=%errorlevel%"

setlocal EnableDelayedExpansion
for /l %%i in (1 1 %line_count%) do echo(!foo[%%i]!
endlocal

pause
goto :eof


:test6
set "in_file=temp.txt"
set "n=0"

<"%in_file%" (
	for /f %%i in ('type "%in_file%"^|find /c /v ""') do set "n=%%i" &for /l %%j in (1 1 %%i) do (
		set "%~1[%%j]=" &set /p "%~1[%%j]="
	)
)

exit /b %n%

temp.txt

Code: Select all

) el
kkk ww

! % < > | & "

As a side note: Defining hundreds of variables for all of the lines is most of the time unnecessary and an indicator for a fundamental design problem in your code.

Steffen

[sincos2007]

Hi Steffen,

In your code, if add “setlocal EnableDelayedExpansion” to beginning of function test6 and “endlocal” at end of test6, how could you make it work?

Thanks

[aGerman]

if add “setlocal EnableDelayedExpansion” to beginning of function test6 and “endlocal” at end of test6

There is NO REASON to do that and it wouldn't work anymore.

Steffen