Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

How to get right value in loop in DOS shell script

Posted on 2012-03-30
16
Medium Priority
?
431 Views
Last Modified: 2012-04-03
Would like to get the right value in this script:

@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A
for /l %%i in (1,1,%N% ) do (
  @echo %var%
  if %%i lss 3 (
    set %var%=B
  ) else (
   if %%i lss 6 (
     set %var%=C
   ) else (
     set %var%=D
   )
  )
)

Expecting the output as follows
A
B
C
C
C
D
D
D
D
D
Actually not. Can any gurus help me out?
0
Comment
Question by:jl66
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 11
  • 2
  • 2
  • +1
16 Comments
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790033
Providing you do have to set a variable to you values, A, B, C, D, then this will do it quite nicely.
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10

for /l %%i in (1,1,%N%) do (
  if %%i lss 6 (
    if %%i lss 3 (
      if %%i lss 2 (
        set var=A
      ) else (
        set var=B
      )
    ) else (
      set var=C
    )
  ) else (
    set var=D
  )
  echo !var!
)

Open in new window

0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790047
If you want to pre-set var to A and place ECHO at the start of the loop then you will need this:
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A

for /l %%i in (1,1,%N%) do (
  echo !var!
  if %%i lss 5 (
    if %%i lss 2 (
      set var=B
    ) else (
      set var=C
    )
  ) else (
    set var=D
  )
)
exit /b

Open in new window

0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790053
Are you sure you want:

    A B CCC DDDDD

instead of:

    A BB CCC DDDD

?
0
Get free NFR key for Veeam Availability Suite 9.5

Veeam is happy to provide a free NFR license (1 year, 2 sockets) to all certified IT Pros. The license allows for the non-production use of Veeam Availability Suite v9.5 in your home lab, without any feature limitations. It works for both VMware and Hyper-V environments

 
LVL 11

Expert Comment

by:paultomasi
ID: 37790060
Similarly, you could place the ECHO at the end of the loop (as in the first program above) and pre-set var to A like this:
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A

for /l %%i in (1,1,%N%) do (
  if %%i lss 6 (
    if %%i lss 3 (
      if %%i gtr 1 (
        set var=B
      )
    ) else (
      set var=C
    )
  ) else (
    set var=D
  )
  echo !var!
)

Open in new window

0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790073
Here are two other methods (pre-processing and post-processing var):
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A

for /l %%i in (1,1,%N%) do (
  echo !var!
  if %%i equ 1 set var=B
  if %%i equ 2 set var=C
  if %%i equ 5 set var=D
)

Open in new window

@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A

for /l %%i in (1,1,%N%) do (
  if %%i equ 2 set var=B
  if %%i equ 3 set var=C
  if %%i equ 6 set var=D
  echo !var!
)

Open in new window

0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790077
This is another way you can do it:
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=9
set var=ABCCCDDDDD

for /l %%i in (0,1,%N%) do (
  echo !var:~%%i,1!
)

Open in new window

0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37790079
Finally, here's the shortest way of doing it:
@for %%i in (A B C C C D D D D D) do @echo %%i

Open in new window

Yep! Just a one-liner!

Or like this:
@echo off
set var=A B C C C D D D D D

for %%i in (%var%) do echo %%i

Open in new window

0
 
LVL 11

Accepted Solution

by:
paultomasi earned 1440 total points
ID: 37790227
YOUR ORIGINAL CODE. See the necessary changes below:
@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A

for /l %%i in (1,1,%N% ) do (
  echo !var!
  if %%i lss 2 (
    set var=B
  ) else (
   if %%i lss 5 (
     set var=C
   ) else (
     set var=D
   )
  )
)

Open in new window

0
 
LVL 71

Assisted Solution

by:Qlemo
Qlemo earned 400 total points
ID: 37791111
There is an obvious difference between
   set %var%=b
and
   set var=b

What Paul showed in all length above appears to be what you were really after, because the original way of setting would set the var named like the contents of %var% to be set. Example:
@echo on
setlocal EnableDelayedExpansion
set var=A
set A=1
set %var%=2
echo %var%, !%var%!

Open in new window

0
 
LVL 38

Assisted Solution

by:Gerwin Jansen, EE MVE
Gerwin Jansen, EE MVE earned 160 total points
ID: 37791786
Hi, I would just correct your script like this:

echo off
SETLOCAL ENABLEDELAYEDEXPANSION

set N=10
set var=A
for /l %%i in (1,1,%N% ) do (
  @echo !var!
  if %%i lss 3 (
    set var=B
  ) else (
   if %%i lss 6 (
     set var=C
   ) else (
     set var=D
   )
  )
)

Open in new window


Output is:

A
B
B
C
C
C
D
D
D
D
0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37791883
gerwinjansen

I think it was more challenging doing "A B CCC DDDD" which now leads me to think this may have in fact been a classroom exercise.

jl66 specified the following output:

    A
    B
    C
    C
    C
    D
    D
    D
    D
    D

I queried this in http:#37790053 however, there has been no feedback suggesting otherwise.
0
 

Author Closing Comment

by:jl66
ID: 37792342
Thanks a lot for everyone. Paul really made a big effort. Qlemo points out the key: I forgot the expression of the variable in loop: !xxx!.
No, this is not a classroom homework!
0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37792496
jl66

It wouldn't have mattered even if it were a classroom exercise because you had done nearly all the work yourself anyway.

Qlemo did well to point out your wrong use of 'set %var%=value'.

Of course, the other problem relates to using '%var%' instead of '!var!' however, this was not explicitly pointed out to you - you likely gathered this looking at solutions. Apologies for not pointing out these two obvious issues from the onset.
0
 
LVL 38

Expert Comment

by:Gerwin Jansen, EE MVE
ID: 37793045
@paul, when looking at the original code, the output specified by OP is wrong, imho, my output is right :-) Anyway, OP learned some here...
0
 
LVL 11

Expert Comment

by:paultomasi
ID: 37793197
gerwinjansen
You're probably right. Maybe I was reading more into the question than there really was.

jl66
Perhapss you would like to confirm which output you intended; column 1 or column 2:
           Column 1       Column 2

               A             A
               B             B
               C             B
               C             C
               C             C
               D             C
               D             D
               D             D
               D             D
               D             D

Open in new window

0
 

Author Comment

by:jl66
ID: 37801503
Not compromise anything. Both are right. The point is that as mentioned before I forgot !var! in loop. Thank all of you so much.
0

Featured Post

Visualize your virtual and backup environments

Create well-organized and polished visualizations of your virtual and backup environments when planning VMware vSphere, Microsoft Hyper-V or Veeam deployments. It helps you to gain better visibility and valuable business insights.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Using dates in 'DOS' batch files has always been tricky as it has no built in ways of extracting date information.  There are many tricks using string manipulation to pull out parts of the %date% variable or output of the date /t command but these r…
TOMORROW TOMORROW.BAT is inspired by a question I get asked over and over again; that is, "How can I use batch file commands to obtain tomorrow's date?" The crux of this batch file revolves around the XCOPY command - a technique I discovered w…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…

618 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question