printf & sprintf: variable number formats

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks,

I was searching for a while but I cant find any answer.

Is there a possible to make the numbers in the format-string changable?

    sprintf "%05i", $myInt;
[download]

Instead of the 5 I'd like to be able to put a varibale here but this fails allready because the 'i' for integers would be recognized as part of the variable:

    $int = 5; sprintf "%0$inti", myInt;
[download]

Is there a solution beside a long switch?

Thanks in advance, Carl

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Re: printf & sprintf: variable number formats by duff (Parson) on Jan 06, 2004 at 16:35 UTC
There are several ways to do this. Here are two: `$int = 5; sprintf "%0${int}i", $myint; $int = 5; sprintf "%0*i", $int, $myint;` [download] duff	[reply] [d/l]
Re: Re: printf & sprintf: variable number formats by Anonymous Monk on Jan 06, 2004 at 16:50 UTC
wow, that was fast, thanks, Carl	[reply]
Re: printf & sprintf: variable number formats by dragonchild (Archbishop) on Jan 06, 2004 at 16:35 UTC
`$int = 5; sprintf "%0${int}i", $myInt;` [download] You were missing the curly-braces around the variable name. ------ We are the carpenters and bricklayers of the Information Age. Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.	[reply] [d/l]
Re: printf & sprintf: variable number formats by flounder99 (Friar) on Jan 06, 2004 at 19:34 UTC
A simple concat works, `$int = 5; printf "%0" . $int . "i", $myInt;` [download] it just isn't as pretty. But it also works with constants `use constant COLWIDTH => 5; $int = 5; printf "%0" . COLWIDTH . "i", $myInt;` [download] -- flounder	[reply] [d/l] [select]
Re: Re: printf & sprintf: variable number formats by duff (Parson) on Jan 06, 2004 at 19:41 UTC
Good point. I should probably have mentioned that very thing about `printf "%0*i", $int, $myint;` too duff	[reply] [d/l]
Re: printf & sprintf: variable number formats by Not_a_Number (Prior) on Jan 06, 2004 at 19:01 UTC
Just a small additional remark. It would appear that `"%d"` is preferable to `"%i"`, based on this extract from perldoc sprintf: Finally, for backward (and we do mean "backward") compatibility, Perl permits these unnecessary but widely-supported conversions: `%i`a synonym for `%d` (etc) So prefer `sprintf "%0${int}d"` or whatever... dave	[reply] [d/l] [select]
Re: printf & sprintf: variable number formats by Roger (Parson) on Jan 07, 2004 at 14:48 UTC
TIMTOWTDI. `use strict; use warnings; use constant LEN => 5; my $n = 12; my $str = '0' x (LEN-length($n)) . $n; print "$str";` [download] Output is as expected - `00012` [download]	[reply] [d/l] [select]