Question

How can I use a batch file to loop through non-integer values?

I’m trying to run my application multiple times with different parameters between 0 and 1 as follows:

!! DO NOT RUN THIS !!
set application=C:\path\to\my\application.exe

for /L %%p in (0, 0.05, 1) do (
  md %%p
  cd %%p
  START %application% %%p
  cd ..
)

But running the above code sends me into an infinite loop, I guess because for /L is looking for integer arguments and 0.05 is converted to 0.

Is it possible to loop through non-integer values using a batch file?

Answer 1

No it’s not possible, as cmd.exe can’t handle in any way real values.

But you can count integers and calculate later the real value.

setlocal EnableDelayedExpansion
for /L %%p in (0, 5, 100) do (
  set "value=00%%p"
  set "value=!value:~-3!"
  set "prefix=!value:~0,1!"
  set "postfix=!value:~-2!"
  set "num=!prefix!.!postfix!"
  md !num!
  pushd !num!
  START %application% !num!
  popd
)

The code counts now form 0 to 100.
Each number will prefixed with 00 to ensure that each number has at least three digits (like 2->002).
Then I take only the last three characters, so all numbers have the same length.

5->005->005
15->0015->015

Then the code splits the number into two part

015->prefix=0 postfix=15

Then set "num=!prefix!.!postfix!" places the dot between the two parts