tiennm99
3bc4fd846b
The README now covers only what the tool does and how to run it: setup, options, tdl flag pass-through, subset exports, resume semantics, the failure modes it guards against, and exit codes. Flags are documented from tdl's own source rather than assumed: dl -f takes the exported JSON while dl -i/-e are file-extension filters, and the expression filter is chat export -f. Chats are addressed by id or domain.
5.0 KiB
telegram-exporter
Export a Telegram chat's media to a WebDAV server, using far less local disk than the chat's total size.
run.sh runs tdl and
rclone as a rolling pipeline: tdl downloads into a small
staging directory while rclone concurrently moves finished files to WebDAV and
deletes the local copies. Local disk only ever holds the files in flight plus
one sync interval of throughput, so a multi-terabyte chat exports fine on a
small disk. Telegram caps a single file at 2 GB (4 GB from premium uploaders),
so a few dozen GB of staging covers the worst case regardless of chat size.
This is needed because tdl can only write to a local directory — it has no
rclone integration and no remote destination of any kind (tdl dl -d takes a
filesystem path; tdl --storage is its session database, not an output target).
tdl downloads over MTProto with a user account, so Bot API limits do not apply:
full history is readable and there is no 20 MB download cap.
Requirements
- tdl — https://docs.iyear.me/tdl/getting-started/installation/
- rclone — https://rclone.org/install/
- bash. On Windows, run under WSL or Git Bash.
Setup
Both steps are one-time.
# 1) log in to Telegram with your user account (phone + code + 2FA)
tdl login
# 2) create the WebDAV remote
rclone config create tg-webdav webdav \
url=https://dav.example.com/remote.php/dav/files/you \
vendor=other user=YOU pass=SECRET
rclone lsd tg-webdav: # verify it works
Usage
./run.sh -r tg-webdav:tg-export -c @mygroup
That is the whole flow. It exports the chat's message metadata to
export.json, then downloads and uploads concurrently until finished. Progress
and warnings go to stderr; press Ctrl-C at any point and it stops cleanly.
Options
| Flag | Meaning |
|---|---|
-r REMOTE:PATH |
Required. rclone destination, e.g. tg-webdav:tg-export |
-c CHAT |
Chat to export when the JSON does not exist yet: @username or a numeric chat id |
-f FILE |
Export JSON to download from (default export.json) |
-d DIR |
Staging directory (default ./staging) |
-i SECONDS |
Seconds between rclone sweeps (default 60) |
-a AGE |
rclone --min-age, a second guard against moving files still being written (default 2m) |
-h |
Help |
Anything after -- is passed straight to tdl dl:
./run.sh -r tg-webdav:tg-export -- -t 4 -l 1 # calmer parallelism, fewer flood waits
./run.sh -r tg-webdav:tg-export -- -i mp4,mkv # only these file extensions
./run.sh -r tg-webdav:tg-export -- -e jpg,png # skip these file extensions
tdl defaults to -t 8 -l 4, which is aggressive; lower it if you hit flood
waits on a large export.
Exporting a subset
Generate the JSON yourself when you want a narrower export, then point -f at
it:
tdl chat export -c @mygroup -T id -i 1000,5000 --all --with-content -o part.json
./run.sh -r tg-webdav:tg-export -f part.json
tdl chat export takes -T time|id|last with -i as the range, and -f as an
expression filter over message fields (-f - lists the available fields).
Resuming
Re-run the same command. Both legs resume independently and nothing is downloaded or uploaded twice.
Keep the same export.json between runs: --skip-same compares against the
staging directory, which is empty once files have moved to WebDAV, so
cross-run deduplication rests on tdl's own --continue tracking. If you must
start from a fresh export, narrow it to the missing message-id range
(-T id -i <last>,<max>) rather than re-downloading everything.
What it guards against
- Partial uploads. tdl writes
<name>.tmpand renames on completion, so every sweep excludes*.tmp. Age alone is not a completion signal: a download stalled by a flood wait stops touching its.tmp, which would then be uploaded half-written and lose its resume point. - Directories vanishing under tdl.
--delete-empty-src-dirsruns only in the final sweep, and the staging directory is recreated after every sweep. Removing a directory under a running tdl makes it fail to create its next file. - Orphaned downloads. tdl is stopped on exit, Ctrl-C, or
SIGTERM, so no download keeps running after the script is gone. - A failed run looking finished. The unrestricted final sweep happens only after tdl exits 0. An interrupted or crashed run gets the age-guarded sweep and keeps staging for the next attempt.
- A dead remote filling the disk. Five consecutive rclone failures abort the run instead of letting staging grow unbounded.
Exit codes: 0 success, 2 usage error, 3 rclone failure, 130/143
interrupted, anything else is tdl's own exit code.
Limits
- Streaming with no staging at all (piping download chunks straight into a
WebDAV
PUT) is not possible with tdl and would require custom code. - The script is bash; the two tools it drives are cross-platform, but Windows needs WSL or Git Bash.