Hi, thank you for this great work!

I am working with small RNA sequencing data, my command is as follows:

echo "umi_tools extract --bc-pattern='.+(?P<discard_1>AACTGTAGGCACCATCAAT){s<=2}(?P<umi_1>.{12})(?P<discard_2>.*)' --extract-method='regex' --quality-encoding=phred33 --quality-filter-threshold=20 -I test_raw.fastq.gz -S test_extract.fastq -L test_extract.log" | rush -k 'echo "{}"'

result：
umi_tools extract --bc-pattern='.+(?P<discard_1>AACTGTAGGCACCATCAAT){s<=2}(?P<umi_1>.test_extract.log)(?P<discard_2>.*)' --extract-method='regex' --quality-encoding=phred33 --quality-filter-threshold=20 -I test_raw.fastq.gz -S test_extract.fastq -L test_extract.log

"{12}" to "test_extract.log", because: {n}, nth field in delimiter-delimited data. (Same in GNU parallel)

but we want (do nothing with the input):
umi_tools extract --bc-pattern='.+(?P<discard_1>AACTGTAGGCACCATCAAT){s<=2}(?P<umi_1>.{12})(?P<discard_2>.*)' --extract-method='regex' --quality-encoding=phred33 --quality-filter-threshold=20 -I test_raw.fastq.gz -S test_extract.fastq -L test_extract.log

So, how to output {12} directly ?

Thanks in advance!