For Loop counting from 1 to n in a windows bat script

Question

I need to run a windows command n times within a bat script file. I know how to do this in various programming languages but cannot manage to get it right on the windows command line :-(

I would expect something like either

for(int i = 0; i < 100; i++) {
   // do something
}

or even this (though not entirely seriously)

1.upto(100, {
   // do something
}) 

Thanks!

EDIT

I can write a program in java, perl, c or whatever that will generate a bat script that looks like this

for %%N in (1 2 3 4 5 6 7 8 9 10 11 12) do echo %%N

and so on. Or even "better":

echo 1
echo 2
echo 3
echo 4
echo 5
echo 6
echo 7
echo 8
echo 9
echo 10
echo 11
echo 12

and then execute it... But the thing is that I need a concise way to specify a range of numbers to iterate through within the script.

Thanks!

Solution 1

You can do it similarly like this:

ECHO Start of Loop

FOR /L %i IN (1,1,5) DO (
  ECHO %i
)

The 1,1,5 is decoded as:

(start,step,end)

Also note, if you are embedding this in a batch file, you will need to use the double percent sign (%%) to prefix your variables, otherwise the command interpreter will try to evaluate the variable %i prior to running the loop.

Solution 2

Directly from the command line:

for /L %n in (1,1,100) do @echo %n

Using a batch file:

@echo off
for /L %%n in (1,1,100) do echo %%n

Displays:

1
2
3
...
100

Solution 3

Syntax is

FOR %%A IN (1 2 3) DO ECHO %%A

Good article here and XP specifics here

Comments

[Srinivasan MK]

The answers here are perfectly good, but for the love of God...batch? Really? I would highly recommend moving to a more modern language.

[wolfgangsz]

It doesn't sound like he's got a choice in the matter.

[Srinivasan MK]

I haven't seen anything that implies there is no choice. As a matter of fact he says he can write in "whatever" language, so I would say that without further information it sounds like he does have a choice.

[raoulsson]

Guys, I need to deploy code THAT is written in a modern language BY a script...

[Srinivasan MK]

That still doesn't explain why batch scripting is required.

[JSchlather]

May it is or isn't required - sometimes it is the right tool for the job. You can't guarantee powershell, let alone bash, python, perl, etc. be installed on a Windows XP or 2003 server box. Batch is a perfectly acceptable solution.

[JSchlather]

Also, there is a clever trick in batch script that uses a sub-routine to call ping localhost in a loop, effectively pausing the script 1 second for each ping. It is a relatively simple (and portable) way to get the script to pause and leverage a loop as documented here.

[Dennis Williamson]

"ECHO Start of Loop" will be executed at each step, not just the start.

[Dennis Williamson]

Also, using an @ sign will supress printing of the commands as they are executed from the command line. "... DO @( ..."

[raoulsson]

This works only with the /L after the "FOR". Why's that?

[Srinivasan MK]

Do a For /? and you will find: FOR /L %variable IN (start,step,end) DO command [command-parameters] The set is a sequence of numbers from start to end, by step amount. So (1,1,5) would generate the sequence 1 2 3 4 5 and (5,-1,1) would generate the sequence (5 4 3 2 1)

[nwgat]

what if the number sequence is 0001 to 00100+ etc?

[i486]

It is better to use %%i in your text and add comment that it is %i for direct execution at command line. Most users will test it in BAT file and try to find the reason why they get error (like me).

[grenix]

The examples using "for /L ..." are didactically more pleasant to me (expecially serverfault.com/a/59026/559613), but i like the external links you provided