LogFilter

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Pipeline-based log filtering for VS Code. Write .lf rule files to filter, extract, and deduplicate log content — preview results instantly.

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Usage Show

Quick Start

Open any .log file and click CreateLogFilterPro in the editor title bar
Edit the .lf file with rules:

# Comments start with #
ERROR                                    # Keep lines matching regex
\[(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\] # Extract capture groups
!dedupe                                  # Commands start with !

Go back to the .log file and click OpenPreview, or press Ctrl+Enter on any rule in the .lf file

Rule Syntax

Type	Description
`# comment`	Line must start with `#` followed by a space
`regex`	Keep matching lines; if capture groups `()`, extract only captured content
`!command`	Operate on the entire line set

Commands

Command	Description
`!dedupe`	Remove duplicate lines globally
`!dedupe-consecutive`	Remove consecutive duplicates (`uniq`)
`!count`	Merge duplicates, append count `(N)`
`!count-consecutive`	Count consecutive duplicates (`uniq -c`)
`!sort`	Sort lines (`-desc`, `-regex <pattern>`, `-int`, `-drop-unmatched`, `-skip-line <N>`)
`!pivot`	Cross-tabulation (`-p` pattern, `-r` rows, `-c` cols, `-v` values, `-f` filter, `-func` aggregator, `-view tree\\|list\\|csv\\|tab`, `-table-view-format compact\\|aligned`)

Parameters can span continuation lines (indented lines starting with -):

!pivot -p (\d+\.\d+\.\d+\.\d+).*?(\d{2}):
  -n 1:IP
  -n 2:Hour
  -r IP
  -c Hour
  -func count

Pipeline

Each rule's output feeds into the next:

Raw log → Rule 1 → Rule 2 → ... → Preview

Example — extract unique error IPs:

Input:
  ERROR [192.168.1.1] timeout
  INFO  [10.0.0.5]   heartbeat
  ERROR [192.168.1.1] retry

Rule 1: ERROR                        → 2 lines (ERROR only)
Rule 2: \[(\d{1,3}\.\d+\.\d+\.\d+)\] → 2 lines (192.168.1.1, 192.168.1.1)
Rule 3: !dedupe                      → 1 line  (192.168.1.1)

Editor Features

CreateLogFilterPro — Create .lf from current .log (editor title button)
OpenPreview — Run all rules and show preview
▶ Filter (Ctrl+Enter) — Run from rule 1 to the current line
Ctrl+Enter (any line) — Run nearest valid rule above cursor
Ctrl+/ — Toggle comment
Syntax highlighting — Comments (green), commands (purple), regex (default)

Install

npm install
npm run compile

Press F5 in VS Code to launch an Extension Dev Host.

Or install from the VS Code Marketplace.

License

MIT

LogFilterPro

zhanwangfeng