Home

Awesome

hl Build Status Coverage Status

A fast and powerful log viewer and processor that translates JSON or logfmt logs into a pretty human-readable format. High performance and convenient features are the main goals.

Features overview

Performance comparison chart

Performance comparison with humanlog, hlogf and fblog on a 2.3 GiB log file

performance chart

Installation options

Examples

Screenshot

screenshot-light screenshot-dark

See other screenshots

Features and usage

Concatenation of multiple log files

Support for compressed (bzip2, gzip, xz, zstd) log files

Automatic usage of pager

Quick filtering by log level

Using live log streaming

Filtering by field values

Performing complex queries

Filtering by time range

Hiding or revealing selected fields

Sorting messages chronologically

Sorting messages chronologically with following the changes

Configuration files

Default configuration file

Environment variables

Precedence of configuration sources (from lowest priority to highest priority)

Environment variables examples

Themes

Stock themes

Selecting current theme

Selecting themes with preview

To select themes with preview fzf tool can be used like this:

hl --list-themes | fzf --preview-window="top,80%" --preview="head -n 100 example.log | hl -c --theme {}"

Custom themes

Used terminal color schemes

iTerm2

Alacritty

Complete set of options and flags

JSON and logfmt log converter to human readable representation

Usage: hl [OPTIONS] [FILE]...

Arguments:
  [FILE]...  Files to process

Options:
      --config <FILE>                    Configuration file path [env: HL_CONFIG=]
  -s, --sort                             Sort messages chronologically
  -F, --follow                           Follow input streams and sort messages chronologically during time frame set by --sync-interval-ms option
      --tail <N>                         Number of last messages to preload from each file in --follow mode [default: 10]
      --sync-interval-ms <MILLISECONDS>  Synchronization interval for live streaming mode enabled by --follow option [default: 100]
      --paging <WHEN>                    Control pager usage (HL_PAGER or PAGER) [env: HL_PAGING=] [default: auto] [possible values: auto, always, never]
  -P                                     Handful alias for --paging=never, overrides --paging option
      --help                             Print help
  -V, --version                          Print version

Filtering Options:
  -l, --level <LEVEL>    Filter messages by level [env: HL_LEVEL=]
      --since <TIME>     Filter messages by timestamp >= <TIME> (--time-zone and --local options are honored)
      --until <TIME>     Filter messages by timestamp <= <TIME> (--time-zone and --local options are honored)
  -f, --filter <FILTER>  Filter messages by field values [k=v, k~=v, k~~=v, 'k!=v', 'k!~=v', 'k!~~=v'] where ~ does substring match and ~~ does regular expression match
  -q, --query <QUERY>    Filter using query, accepts expressions from --filter and supports '(', ')', 'and', 'or', 'not', 'in', 'contain', 'like', '<', '>', '<=', '>=', etc

Output Options:
      --color [<WHEN>]        Color output control [env: HL_COLOR=] [default: auto] [possible values: auto, always, never]
  -c                          Handful alias for --color=always, overrides --color option
      --theme <THEME>         Color theme [env: HL_THEME=] [default: universal]
  -r, --raw                   Output raw source messages instead of formatted messages, which can be useful for applying filters and saving results in their original format
      --no-raw                Disable raw source messages output, overrides --raw option
      --raw-fields            Output field values as is, without unescaping or prettifying
  -h, --hide <KEY>            Hide or reveal fields with the specified keys, prefix with ! to reveal, specify '!*' to reveal all
      --flatten <WHEN>        Whether to flatten objects [env: HL_FLATTEN=] [default: always] [possible values: never, always]
  -t, --time-format <FORMAT>  Time format, see https://man7.org/linux/man-pages/man1/date.1.html [env: HL_TIME_FORMAT=] [default: "%b %d %T.%3N"]
  -Z, --time-zone <TZ>        Time zone name, see column "TZ identifier" at https://en.wikipedia.org/wiki/List_of_tz_database_time_zones [env: HL_TIME_ZONE=] [default: UTC]
  -L, --local                 Use local time zone, overrides --time-zone option
      --no-local              Disable local time zone, overrides --local option
  -e, --hide-empty-fields     Hide empty fields, applies for null, string, object and array fields only [env: HL_HIDE_EMPTY_FIELDS=]
  -E, --show-empty-fields     Show empty fields, overrides --hide-empty-fields option [env: HL_SHOW_EMPTY_FIELDS=]
      --input-info <VARIANT>  Show input number and/or input filename before each message [default: auto] [possible values: auto, none, full, compact, minimal]
  -o, --output <FILE>         Output file

Input Options:
      --input-format <FORMAT>       Input format [env: HL_INPUT_FORMAT=] [default: auto] [possible values: auto, json, logfmt]
      --unix-timestamp-unit <UNIT>  Unix timestamp unit [env: HL_UNIX_TIMESTAMP_UNIT=] [default: auto] [possible values: auto, s, ms, us, ns]
      --allow-prefix                Allow non-JSON prefixes before JSON messages [env: HL_ALLOW_PREFIX=]
      --delimiter <DELIMITER>       Log message delimiter, [NUL, CR, LF, CRLF] or any custom string

Advanced Options:
      --interrupt-ignore-count <N>  Number of interrupts to ignore, i.e. Ctrl-C (SIGINT) [env: HL_INTERRUPT_IGNORE_COUNT=] [default: 3]
      --buffer-size <SIZE>          Buffer size [env: HL_BUFFER_SIZE=] [default: "256 KiB"]
      --max-message-size <SIZE>     Maximum message size [env: HL_MAX_MESSAGE_SIZE=] [default: "64 MiB"]
  -C, --concurrency <N>             Number of processing threads [env: HL_CONCURRENCY=]
      --shell-completions <SHELL>   Print shell auto-completion script and exit [possible values: bash, elvish, fish, powershell, zsh]
      --man-page                    Print man page and exit
      --list-themes                 Print available themes and exit
      --dump-index                  Print debug index metadata (in --sort mode) and exit

Performance

performance chart