Illumina_PE_reads-how to add the barcode sequence of read1 to the beginning of read2

[lueny]

I have read1.fastq and read2.fastq from the same lane.
At the beginning of read1, there are 7-9bp barcodes, but no barcode in read2.
so I want to add the barcode sequence of read1 to the the beginning of read2.

How to do this? thanks !