Splitting one large file into many if the text in a column doesn't match the text in the one before it

Question

I searched for awhile and couldn\'t find a response to this. I have a standard tsv file with the following format:

1    100    101    350    A
1    101    102            


        

Answer 1

With awk

awk '{out = "File" $NF ".txt"; print >> out; close(out)}' file

More efficient, not closing the destination file after every line:

awk '
    $NF != dest {if (out) close(out); dest = $NF; out = "File" dest ".txt"} 
    {print >> out}
' file