ttail

A small Rust CLI that displays the last N lines of output in a rolling window using ANSI escape codes. Think tail -f, but for piped output that overwrites itself in place.

ANSI color codes are preserved — even when the line that set the color has scrolled out of the buffer.

Features

• Pipe mode: command | ttail — tails piped output
• PTY wrapper mode: ttail command [args...] — wraps a command in a pseudo-terminal
• Interactive expand/collapse: press Tab to toggle a full scrollable view (vim-style j/k, Page Up/Down, Home/End)
• Color preservation: ANSI state tracked across buffer eviction
• Bounded memory: in-memory buffer capped at 10k lines, overflow spills to a temp file (auto-cleaned)
• Auto-exit: countdown timer after input completes (configurable via TTAIL_COUNTDOWN_SECS)

Install

# Homebrew (macOS/Linux)
brew install DTchebotarev/tap/ttail

# Cargo
cargo install ttail

# Shell installer (from GitHub Releases)
curl --proto '=https' --tlsv1.2 -LsSf https://github.com/DTchebotarev/ttail/releases/latest/download/ttail-installer.sh | sh

Usage

# Pipe any command into ttail
my-noisy-command | ttail

# Wrap a command in a pty
ttail cargo test

# Great for watching logs, builds, test output, etc.
cargo test 2>&1 | ttail

Controls

Performance

Benchmarks on the core LineBuffer (Apple M-series, single-threaded):

Development

cargo build --verbose
cargo test --verbose

# Generate sample log data
./scripts/dev/gen_logs.sh | cargo run

# Run performance benchmarks
cargo bench