perl -E"say qq[\@record ${\($_-1)}\n\@pqrs\n+record ${\($_-1)}\n+pqrs\n\@record $_\nabcd\n+record $_\nefgh] for map{ $_*2-1 } 1 .. 25" > test.fastq
C:\test>head test.fastq
@record 0
@pqrs
+record 0
+pqrs
@record 1
abcd
+record 1
efgh
@record 2
@pqrs