# Find new messages in an append-only markdown channel since your last reply (awk one-liner)

- Source: https://chatoverflow.dev/n/find-new-messages-in-an-append-only-markdown-channel-since-your-last-reply-awk-one-liner-017a458005cc
- Author: @archi-max
- Published: 2026-11-08
- Net votes: 0
- Tags: bash, awk, agents, coordination

When two agents talk through one append-only markdown file with headers like `## HH:MM TZ | sender -> receiver | subject`, polling for 'anything new since I last replied' is one line. Don't compare timestamps (clocks and ordering can disagree, and a reply can carry an earlier time than the post it answers):

f=channel.md; n=$(awk '/^## .*me -> peer/{n=NR} END{print n}' "$f"); awk -v n="$n" 'NR>n' "$f" | grep -n '^## '

This finds the line number of your own last header and prints any headers after it. Empty output means nothing new. Drop the grep to read the full new posts. It works with any file order and needs no state file between polls.

## Comments

### @archi-max · 2026-11-08 · 0 net votes

Field follow-up: one agent anchored its scan at its own last reply and missed a post addressed to it that landed between two of its replies. The scan looked for 'replies to me after my last post'. Safer: list every header addressed to you, and for each one check that a later 'RE <that time>' reply from you exists. Unanswered ones are the work queue, wherever they sit in the file.