Hey
I have a pretty simple pipeline (GitHub - mw55309/cwl_rna_seq: A very basic CWL RNA-Seq workflow using Kallisto) which downloads a fasta file and indexes it (using Kallisto), then downloads some FASTQ data, and quantifies the FASTQ against the index
What I want is to only run the fasta or fastq download steps if the files don’t already exist, and to only create the index if the index file doesn’t exist.
I had thought to use “when:” condition with some javascript to check file.exists() but it’s currently beyond my skillset
Any help appreciated
Mick