ft

Features

• Recursive tailing for existing files and newly created files.
• Text-only detection to avoid binary noise.
• TUI with scrolling, follow mode, pause/resume, and clear.
• Optional include/exclude glob filters.

Build

cd /Users/zongbaolu/work/folder_tail

go build ./cmd/ft

Usage

./ft [root] [pattern ...]

root must be an existing directory (default is the current working directory). If the first argument is a directory, it is treated as the root; remaining args are patterns.

Development

make test
make build
make run

Flags

• -n number of last lines to show on startup per file (default 10, 0 = start at end)
• -from-start show full contents for existing files from the beginning
• -scan-interval periodic rescan interval (default 5s, 0 disables)
• -absolute show absolute paths
• -include include glob list (comma-separated; matches file name or relative path)
• -exclude exclude glob list (comma-separated; matches file name or relative path)
• -buffer maximum number of lines kept in the TUI buffer (default 10000)
• -max-line-bytes maximum bytes per line before truncation (default 1048576)
• -version print version and exit
• -re / -regex treat patterns as regular expressions
• -r / -R recursive (default true; set -r=false to disable)

Patterns

• Default behavior is recursive; ft ./*.log is equivalent to ft -r ./*.log.
• Patterns are globs by default. Patterns with / (or OS separators) match the relative path; otherwise they match the file name.
• Leading ./ or .\\ is stripped for glob patterns (so ./*.log behaves like *.log).
• To avoid shell expansion, wrap patterns in quotes (for example: ft '.' '*.log').
• Regex mode: use -re / -regex or prefix a pattern with re: (for example: ft -re '.*\\.log$' or ft 're:.*\\.log$').

Examples

ft .
ft ./*.log
ft /var/log '*.log'
ft /var/log -exclude '*.gz'
ft -re /var/log '.*(err|warn).*\\.log$'

Compatibility

• folder-tail is an alias binary that runs the same CLI as ft.

Key bindings

• q / ctrl+c quit
• space pause/resume (still collects new lines)
• f toggle follow mode (Follow auto-jumps to newest lines; Free keeps your scroll position)
• c clear buffer
• p toggle path display (grouped header vs inline)
• arrows / page up/down / [ ] scroll

Notes

• Lines are shown as path: line.
• If a line is still being written (no trailing newline), it is shown with ... and updated when completed.
• Periodic rescans also pull in missed writes if filesystem events were dropped.
• Periodic rescans remove deleted files/directories from the watch set if events were missed.
• Text detection accepts UTF-8 and other non-binary encodings without NUL bytes and rejects common binary signatures/content types.
• When no patterns are provided, common binary extensions (e.g., .wav, .bin, .aiff) are skipped.