Understanding the interception function of variable characters in CMD - China DOS Union Forum

　　In fact, the character interception function of variables in CMD is very practical, but some friends haven't really understood the rules inside. So today I specially wrote the following code, hoping to help novice friends understand the character interception function of variables under CMD.


::code by lxmxn @ cn-dos.net .
::Purpose: To help novices better understand the variable character interception function.
::Date 2006-12-16 .
::Description: Some variables may have empty values after interception, which is normal.
@echo off&setlocal EnableDelayedexpansion
::Set the value of variable var:
set var=0123456789ABCDEF
call :begin
for /l %%a in (1,3,15) do (
    for /l %%b in (1,4,15) do (
        call :printf %%a %%b
    )
)
call :begin
for /l %%a in (1,4,15) do (
    for /l %%b in (-1,-3,-15) do (
        call :printf  %%a %%b
    )
)
call :begin
for /l %%a in (-2,-3,-15) do (
    for /l %%b in (1,4,15) do (
        call :printf  %%a %%b
    )
)
call :begin
for /l %%a in (-1,-4,-15) do (
    for /l %%b in (-2,-3,-15) do (
        call :printf  %%a %%b
    )
)
pause
endlocal&cls&echo.
echo The demonstration is over, press any key to exit...
pause>nul
goto :eof

::Output result:
:printf
    echo %%var:~%1,%2%% The intercepted character is:	!var:~%1,%2!
    goto :eof

::Clear the screen:
:begin
    echo\&pause&cls&echo.
    echo 			The value of variable var is:	%var%
    echo.
    goto :eof

　　　　　　Click here to download the attachment (Getstr.rar)

[ Last edited by lxmxn on 2007-10-31 at 06:33 PM ]

Thanks to brother lxmxn, it has been of great help to beginners like us!

It is suggested that everyone copy the code, save it as a BAT file, and then add a tab character with TAB before "The character after interception is" and "The value of variable var is", so that the display will be neat.

　　Re ccwan :
　
　　Sweat, are you still a newbie?
　　Thanks for the plus points and encouragement. ^_^

　　Re zh159 :

　　Thanks for your proposal and plus points, brother.
　　I spent a long time re-editing the post, but unfortunately, I still didn't achieve a neat display effect in the end. Finally, I had to let everyone download it as an attachment.

So wonderful～～
Why did the font become smaller?

Originally posted by redtek at 2006-12-17 07:47:
So wonderful~~
Why did the font become smaller?

　　What you mentioned about the font becoming smaller, what exactly are you referring to? My theme's font has become larger instead.

Good stuff, learning.

If the characters are too small and hard to read, you can hold down the Ctrl key and then scroll the mouse wheel upward to make them larger, and scroll downward to make them smaller.

　　Adjusted the font, let's see how big the font is now.
　
　　I specifically adjusted the font to be relatively large yesterday, but today when I came to the forum, it suddenly became very small. I don't know the reason.

Classic, newcomers are in for a treat! Hehe

Wonderful~~Bump up this great post~:)

Good stuff, so good that it's hard to describe. It turns out that batch processing has such detailed functions.

Floor1　lxmxn	Posted 2006-12-17 06:35
版主　Posts 4,938　Credits 11,386
In fact, the character interception function of variables in CMD is very practical, but some friends haven't really understood the rules inside. So today I specially wrote the following code, hoping to help novice friends understand the character interception function of variables under CMD. ::code by lxmxn @ cn-dos.net . ::Purpose: To help novices better understand the variable character interception function. ::Date 2006-12-16 . ::Description: Some variables may have empty values after interception, which is normal. @echo off&setlocal EnableDelayedexpansion ::Set the value of variable var: set var=0123456789ABCDEF call :begin for /l %%a in (1,3,15) do ( for /l %%b in (1,4,15) do ( call :printf %%a %%b ) ) call :begin for /l %%a in (1,4,15) do ( for /l %%b in (-1,-3,-15) do ( call :printf %%a %%b ) ) call :begin for /l %%a in (-2,-3,-15) do ( for /l %%b in (1,4,15) do ( call :printf %%a %%b ) ) call :begin for /l %%a in (-1,-4,-15) do ( for /l %%b in (-2,-3,-15) do ( call :printf %%a %%b ) ) pause endlocal&cls&echo. echo The demonstration is over, press any key to exit... pause>nul goto :eof ::Output result: :printf echo %%var:~%1,%2%% The intercepted character is: !var:~%1,%2! goto :eof ::Clear the screen: :begin echo\&pause&cls&echo. echo The value of variable var is: %var% echo. goto :eof 　　　　　　Click here to download the attachment (Getstr.rar) [ Last edited by lxmxn on 2007-10-31 at 06:33 PM ]

Floor2　ccwan	Posted 2006-12-17 06:46
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Thanks to brother lxmxn, it has been of great help to beginners like us!

Floor3　zh159	Posted 2006-12-17 06:51
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It is suggested that everyone copy the code, save it as a BAT file, and then add a tab character with TAB before "The character after interception is" and "The value of variable var is", so that the display will be neat.

Floor4　lxmxn	Posted 2006-12-17 07:41
版主　Posts 4,938　Credits 11,386
Re ccwan : 　　　Sweat, are you still a newbie? 　　Thanks for the plus points and encouragement. ^_^ 　　Re zh159 : 　　Thanks for your proposal and plus points, brother. 　　I spent a long time re-editing the post, but unfortunately, I still didn't achieve a neat display effect in the end. Finally, I had to let everyone download it as an attachment.

Floor5　redtek	Posted 2006-12-17 07:47
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So wonderful～～ Why did the font become smaller?

Floor6　lxmxn	Posted 2006-12-17 07:57
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Originally posted by redtek at 2006-12-17 07:47: So wonderful~~ Why did the font become smaller? 　　What you mentioned about the font becoming smaller, what exactly are you referring to? My theme's font has become larger instead.

Floor7　jmz573515	Posted 2006-12-17 08:01
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Good stuff, learning.

Floor8　lianjiang2004	Posted 2006-12-17 10:03
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Learned. Good post.

Floor9　vkill	Posted 2006-12-17 21:49
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Floor10　ccwan	Posted 2006-12-17 22:03
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If the characters are too small and hard to read, you can hold down the Ctrl key and then scroll the mouse wheel upward to make them larger, and scroll downward to make them smaller.

Floor11　wydos	Posted 2006-12-18 00:07
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Floor12　lxmxn	Posted 2006-12-18 03:21
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Adjusted the font, let's see how big the font is now. 　　　I specifically adjusted the font to be relatively large yesterday, but today when I came to the forum, it suddenly became very small. I don't know the reason.

Floor13　freeapple	Posted 2006-12-18 03:35
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Classic, newcomers are in for a treat! Hehe

Floor14　redtek	Posted 2006-12-24 23:59
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Wonderful~~Bump up this great post~:)

Floor15　xuzhenhui	Posted 2007-01-13 21:41
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Good stuff, so good that it's hard to describe. It turns out that batch processing has such detailed functions.