Usage Guide

Input Sources

File Tailing

Tail a log file (similar to tail -f):

smartlog --file /var/log/myapp.log

SmartLog starts from the end of the file and follows new lines. If the file is truncated or rotated, it automatically continues from the beginning of the new file.

Multi-File Tailing

Watch multiple files simultaneously:

smartlog --file /var/log/app.log --file /var/log/error.log

Each log entry is prefixed with the source filename (e.g., [app.log]). The status bar shows the number of active files.

Stdin Piping

Pipe any command output into SmartLog:

tail -f /var/log/app.log | smartlog
kubectl logs -f my-pod | smartlog
docker logs -f my-container | smartlog

Demo Mode

Running smartlog without --file and without piped stdin starts a demo stream with sample log entries.

Keyboard Shortcuts

Key	Action
/	Enter filter mode
ESC	Exit filter mode / Clear filter / Re-enable auto-scroll
Up or k	Scroll up (pauses auto-scroll)
Down or j	Scroll down
PageUp	Scroll up by one page
PageDown	Scroll down by one page
Home or g	Jump to top
End or G	Jump to bottom (re-enables auto-scroll)
Enter	Apply filter (in filter mode)
w	Toggle line wrapping on/off
l	Cycle log level filter (ALL -> ERROR -> WARN -> INFO -> DEBUG -> ALL)
r	Toggle regex filtering mode
e	Export filtered logs to file
t	Toggle relative timestamp display
T	Cycle color theme
Mouse wheel	Scroll up/down
q	Quit application

Filtering

Text Search

1. Press / to enter filter mode
2. Type your search query (case-insensitive)
3. Press Enter to apply the filter and return to normal mode
4. Press ESC to clear the filter

Matching text is highlighted with a cyan background.

Regex Filtering

Press r to toggle regex mode. When active, the filter input is treated as a regular expression (case-insensitive).

Regex features:

• Patterns like \d+, error|warn, connection.*failed
• Invalid regex patterns are indicated in the status bar
• Uses Rust's regex crate (linear-time, ReDoS-safe)

Log Level Filtering

Press l to cycle through minimum log level filters:

ALL -> ERROR -> WARN -> INFO -> DEBUG -> ALL

Only entries at or above the selected severity are shown. This filter combines with the text/regex filter -- both must match for an entry to be visible.

Relative Timestamps

Press t to toggle relative timestamp display. When enabled, each log entry with a detected timestamp shows a prefix like [3s ago], [5m ago], or [2h ago].

The display auto-refreshes every 30 seconds to keep values current.

Timestamps are extracted from:

• JSON logs: timestamp, ts, time, @timestamp, datetime, date fields (ISO 8601 strings or Unix epoch seconds/milliseconds/microseconds)
• Plain text logs: ISO 8601 or common date/time patterns at the beginning of the line

Color Themes

Use --theme <name> to set the color theme at startup, or press T at runtime to cycle:

Theme	Description
dark	Default theme for dark terminal backgrounds
light	Designed for light terminal backgrounds
solarized	Based on the Solarized color palette
dracula	Based on the Dracula color palette

The current theme name is shown in the status bar.

Export Logs

Press e to export the currently filtered logs to a file.

• Default location: current directory
• Custom location: --export-dir <path>
• Filename format: smartlog_export_<timestamp>_<seq>.log
• The status bar shows confirmation with the file path

Debug Logging

For troubleshooting SmartLog itself:

# Enable debug logging (writes to smartlog_debug.log)
smartlog --verbose --file /var/log/app.log

# Custom debug log path
smartlog --verbose --debug-log /tmp/smartlog-debug.log --file /var/log/app.log

CLI Options

smartlog [OPTIONS] [COMMAND]

Options:
  --file <FILE>          Log file to tail (can be specified multiple times)
  --theme <THEME>        Color theme (dark, light, solarized, dracula)
  --export-dir <DIR>     Directory for exported log files
  --verbose, -v          Enable debug logging
  --debug-log <PATH>     Custom debug log file path

Commands:
  completions            Generate shell completion scripts