in reply to Re^2: Formatting dates while parsing CSV
in thread Add leading zeros to days/months in dates while parsing CSV

I can't replicate your problem with the above source code and Perl 5.14.

If you get this problem with a different program, or different input, you will have to show us that program and that input.

For example, I can provoke that error message by removing an index from the slice after split:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my @fields = 'a' .. 'z';
@fields[ 10, 14, 24, 26] = ('1/2/2016') x 4;
# My change is below
$_ = sprintf '%04d-%02d-%02d', (split m:/:)[ 0, 1 ] for @fields[ 10, 1
+4, 24, 26 ];
say join ',', @fields;

__END__
Missing argument in sprintf at tmp.pl line 8.
Missing argument in sprintf at tmp.pl line 8.
Missing argument in sprintf at tmp.pl line 8.
Missing argument in sprintf at tmp.pl line 8.
a,b,c,d,e,f,g,h,i,j,0001-02-00,l,m,n,0001-02-00,p,q,r,s,t,u,v,w,x,0001
+-02-00,z,0001-02-00

[download]

So, a likely issue is that you did not use the exact code that choroba posted.

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Re^4: Formatting dates while parsing CSV
by BigRedEO (Acolyte) on Jun 14, 2016 at 15:16 UTC
    Wait - I may have figured it out. Later in the code, if those same four fields are empty, I'm simply substituting it with "0000-00-00". I'm guessing that my original "join" statement doesn't care if that field is empty, but sprintf does?
[reply]
      The problem is that the array slice doesn't return undefs when slicing an empty list, it just doesn't return anything: 
      $ perl -wE 'say for ()[2, 1, 0]'

$ perl -wE 'say for ("a")[2, 1, 0]'
Use of uninitialized value in say at -e line 1.

Use of uninitialized value in say at -e line 1.

a

      [download]

      Easy fix: supply the missing fields: 

      $_ = sprintf '%04d-%02d-%02d', ((split m:/:), (0) x 3)[ 2, 0, 1 ] for 
+@fields[ 10, 14, 24, 26 ];

      [download]

      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

      [download]
[reply]
[d/l]
[select]
        So just adding the "(0) x3" will add zeros to any empty date fields, but format if there is an actual date?
[reply]
      Arrays are indexed from 0 in Perl: 
      0         1 2 3                            4  5          6           7
+8 9         10     11        12   13
640399762,1,1,colorant ran out during shot,20,IFC 8112NP,08DX8020212,,
+1,1/31/2016,181315,A82T00154,7674,1/30/2016

      [download]
      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

      [download]
[reply]
[d/l]
[select]
        Yes - but my code is adding a concatenated field to the beginning of each record first.
[reply]

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