I just needed a quick and dirty MRT parser.
This tool ignores most fields from MRT BGP dumps taken from routeviews.org. It spits out a prefix in the first column, then any AS sequences (paths) or sets in subsequent columns. One sequence and/or set per line.
By dropping a lot of inspection, this tool can run fairly quickly (ripe ncc's bgpdump does a lot more string formatting for output):
sds@stkilda:~/proj/mrt-parser$ time zcat bview.20170801.0800.gz > /dev/null
real 0m3.288s
user 0m3.252s
sys 0m0.020s
sds@stkilda:~/proj/mrt-parser$ time ./mrt -f bview.20170801.0800.gz > /dev/null
real 0m23.587s
user 0m23.313s
sys 0m0.120s
sds@stkilda:~/proj/mrt-parser$ time ~/ext/bgpdump/bgpdump -m bview.20170801.0800.gz > /dev/null 2>&1
real 1m40.063s
user 1m30.846s
sys 0m8.477s