count nginx requests by a certain POST pattern

count_requests_by_id.sh

#!/usr/bin/env bash
# The POST string is like
# \"id\"=<some number>
# Count the requests by mid
# The result is like:
# count id
# ... ...

# known search patterns:
# %22mid%22%2A
# %2522mid%2522%253A

access_log=$1

grep -oP '%[^%]+mid%[^%]+%[^%]+[0-9]*' $access_log | sed -ne 's/%\([^%]\+\)mid%\([^%]\+\)%\([^%]\+\)3A\([0-9]\+\)/\4/p' | sort | uniq -c | sort -rn | awk 'BEGIN{print "count", "mid"};{printf("%d 0x%04x\n", $1, $2)};' | column -t