If I recall correctly, the split function should only remove missing values from the end of your input string:

$ perl -e 'print scalar(split /,/,"1,2,3,4")'
4
$ perl -e 'print scalar(split /,/,",2,3,4")'
4
$ perl -e 'print scalar(split /,/,"1,,3,4")'
4
$ perl -e 'print scalar(split /,/,"1,2,,4")'
4
$ perl -e 'print scalar(split /,/,"1,2,3,")'
3
$ perl -e 'print scalar(split /,/,"1,2,,")'
2
[download]

You'd best check perldoc -f split to see what it does in detail.

...roboticus

When your only tool is a hammer, all problems look like your thumb.