# Structured Log Formatter
**Terminal utility to pretty-print JSON-strucutred log lines.**

## Usage

`slfmt` is intended to be used to filter logging output from a process. It
reads from `stdin` and writes to `stdout`. It expects to see a JSON object on
each line of input, and will pretty-print the object to `stdout`. Escape codes
in the log lines (`\n` for newlines, etc.) are supported and will be expanded
in the output.

Any lines that are not valid JSON objects will be printed as-is to `stdout`.

Example:

```bash
./run-server | slfmt
```

Sample Output:

```
---------------------------------------------------------------------------------------
scope:     "server/rest_api"
level:     "ERROR"
ts:
  2025-01-03T08:46:35-06:00 (local)  2025-01-03T14:46:35Z (UTC)
msg:       unhandled exception (DbError)
err:
  ERROR:  relation "users" does not exist
  LINE 1: SELECT id FROM users WHERE id = '43422d65-6874-44ce-b9b3-f8c...
                         ^

stack:
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(519) workerProc
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(450) runTask
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy/routers.nim(271) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/api.nim(65) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/auth.nim(74) extractSession
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(599) createOrUpdateUser
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(384) createOrUpdateRecord
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(497) getAllRows
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(174) setupQuery
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(116) dbError
  [[reraised from:
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(519) workerProc
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(450) runTask
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy/routers.nim(271) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/api.nim(65) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/auth.nim(74) extractSession
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(727) createOrUpdateUser
  ]]



---------------------------------------------------------------------------------------
scope:     "server/rest_api"
level:     "ERROR"
ts:
  2025-01-03T08:46:35-06:00 (local)  2025-01-03T14:46:35Z (UTC)
msg:       unhandled exception (DbError)
err:
  ERROR:  relation "users" does not exist
  LINE 1: SELECT id FROM users WHERE id = '43422d65-6874-44ce-b9b3-f8c...
                         ^

stack:
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(519) workerProc
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(450) runTask
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy/routers.nim(271) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/api.nim(65) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/auth.nim(74) extractSession
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(599) createOrUpdateUser
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(384) createOrUpdateRecord
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(497) getAllRows
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(174) setupQuery
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/db_connector-0.1.0-d68319e3785fa937f0465ea915e942b61b6b5442/db_connector/db_postgres.nim(116) dbError
  [[reraised from:
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(519) workerProc
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy.nim(450) runTask
  /home/username/.local/share/mise/installs/nim/2.2.0/nimble/pkgs2/mummy-0.4.5-cb7f70cd4d6fd3a563e00e664cfbd8cbd3c39b79/mummy/routers.nim(271) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/api.nim(65) :anonymous
  /home/username/projects/server/api/src/main/nim/server_api/auth.nim(74) extractSession
  /home/username/projects/fiber-orm-nim/src/fiber_orm.nim(727) createOrUpdateUser
  ]]

```