BazerUtils.jl

BazerUtils.jl is a package that assembles various functionality that I use on a frequent basis in julia. It is a more mature version of Prototypes.jl where I try a bunch of things out (there is overlap).

The package provides:

• custom_logger: configurable logging with per-level file output, module filtering, and multiple format options (:pretty, :oneline, :json, :logfmt, :syslog, :log4j_standard)
• read_jsonl / stream_jsonl / write_jsonl: deprecated — use JSON.jl v1 with jsonlines=true instead

Installation

BazerUtils.jl is a registered package. You can install from the my julia registry loulouJL via the julia package manager:

> using Pkg, LocalRegistry
> pkg"registry add https://github.com/LouLouLibs/loulouJL.git"
> Pkg.add("BazerUtils")

If you don't want to add a new registry, you can install it directly from github:

> import Pkg; Pkg.add("https://github.com/louloulibs/BazerUtils.jl#main")

Usage

Custom Logging

A configurable logger that lets you filter messages from specific modules and redirect them to different files, with a format that is easy to read and control.

custom_logger(
    "./log/build_stable_sample_multiplier";
    file_loggers=[:warn, :debug],                             # which file loggers to deploy

    filtered_modules_all=[:HTTP],                             # filter across all loggers
    filtered_modules_specific=[:TranscodingStreams],           # filter for stdout and info only

    displaysize=(50,100),                                     # how much to show for non-string messages
    log_format=:oneline,                                      # format for files (see formats below)
    log_format_stdout=:pretty,                                # format for REPL

    cascading_loglevels=false,                                # false = each file gets only its level
                                                              # true  = each file gets its level and above

    create_log_files=true,                                    # separate file per level
    overwrite=true,
    );

Log Formats

Format	Symbol	Description
Pretty	:pretty	Box-drawing + ANSI colors — default for stdout
Oneline	:oneline	Single-line with timestamp, level, module, file:line — default for files
JSON	:json	One JSON object per line — for log aggregation (ELK, Datadog, Loki)
logfmt	:logfmt	key=value pairs — grep-friendly, popular with Splunk/Heroku
Syslog	:syslog	RFC 5424 syslog format
Log4j Standard	:log4j_standard	Apache Log4j PatternLayout — for Java tooling interop

Example output for each:

# :pretty (stdout default)
┌ [08:28:08 2025-02-12] Info |  @ Main[script.jl:42]
└ Processing batch 5 of 10

# :oneline (file default)
[/home/user/project] 2025-02-12 08:28:08 INFO  Main[./script.jl:42] Processing batch 5 of 10

# :json
{"timestamp":"2025-02-12T08:28:08","level":"INFO","module":"Main","file":"script.jl","line":42,"message":"Processing batch 5 of 10"}

# :logfmt
ts=2025-02-12T08:28:08 level=info module=Main file=script.jl line=42 msg="Processing batch 5 of 10"

# :syslog
<14>1 2025-02-12T08:28:08 hostname julia 12345 - - Processing batch 5 of 10

# :log4j_standard
2025-02-12 08:28:08,000 INFO  [1] Main - Processing batch 5 of 10

Note: :log4j still works as a deprecated alias for :oneline and will be removed in a future version.

JSON Lines (deprecated)

The JSONL functions (read_jsonl, stream_jsonl, write_jsonl) are deprecated. Use JSON.jl v1 instead:

using JSON
data = JSON.parse("data.jsonl"; jsonlines=true)       # read
JSON.json("out.jsonl", data; jsonlines=true)           # write

Other stuff

See my other package

• BazerData.jl which groups together data wrangling functions.
• FinanceRoutines.jl which is more focused and centered on working with financial data.
• TigerFetch.jl which simplifies downloading shape files from the Census.