Apparently perl has no limit on line length.

If, however, you are passing parameters to or from perl through the command line then there can be an OS-imposed limit to the total length of the values of the parameters that you pass.

Last year I went through some tsouris (pain) when my perl database program was dropping without warning the last couple of fields that I was passing through to the command line. Someone told me that UNIX systems often limit the length of command-line parameters to some small number, maybe 512 bytes or something like that.