Alternatively (depending on memory constraints), you can simply do:

@array = <>;
[download]

which puts one line in each array index. If you need that substr call, consider this:

@array = <>;
@array = map {  substr($_,0,$x)  } @array;

#or in one step:

@array = map {  substr($_,0,$x)  } <>;
[download]

HTH