Solved

How to get right value in loop in DOS shell script

Posted on 2012-03-30
16
423 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
  • 11
  • 2
  • 2
  • +1
16 Comments
 
LVL 11

Expert Comment

by:paultomasi
Comment Utility
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
Comment Utility
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
Comment Utility
Are you sure you want:

    A B CCC DDDDD

instead of:

    A BB CCC DDDD

?
0
 
LVL 11

Expert Comment

by:paultomasi
Comment Utility
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
Comment Utility
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
Comment Utility
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
Comment Utility
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 360 total points
Comment Utility
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
Maximize Your Threat Intelligence Reporting

Reporting is one of the most important and least talked about aspects of a world-class threat intelligence program. Here’s how to do it right.

 
LVL 68

Assisted Solution

by:Qlemo
Qlemo earned 100 total points
Comment Utility
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 37

Assisted Solution

by:Gerwin Jansen
Gerwin Jansen earned 40 total points
Comment Utility
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
Comment Utility
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
Comment Utility
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
Comment Utility
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 37

Expert Comment

by:Gerwin Jansen
Comment Utility
@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
Comment Utility
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
Comment Utility
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

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

This Windows batch file is useful for organizing image files from a digital camera or other source, but can have many other uses.  It simply renames the file(s) to match their create date.  For example, if you took a picture today at 1:40pm and the …
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…
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…
Access reports are powerful and flexible. Learn how to create a query and then a grouped report using the wizard. Modify the report design after the wizard is done to make it look better. There will be another video to explain how to put the final p…

743 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

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now