tail

Files

SKILL.mdagentsreferencesscripts

Install

Install only this skill with npx skills

npx skills add alisonaquinas/llm-shared-skills --skill 'tail' -g -y

Install the containing skill bundle

/plugin install shared-skills@llm-skills

Download tail-skill.zip

This skill is bundled inside shared-skills. Use npx skills when you only want this skill, or install the bundle once to make every included skill available through the plugin marketplace flow. Browse the full skill bundle repository at github.com/alisonaquinas/llm-shared-skills.

Invoke

Invoke this skill after installation

/shared-skills:tail

SKILL.md

name: tail description: Sample file endings and monitor growing logs with tail for real-time log viewing, end-of-file inspection, and live log following. Use when the agent needs the last N lines or bytes, follow-mode monitoring of append-only files, or track log file rotation.

Sample and monitor file endings and live-updating streams.

Quick Start

Verify tail is available: tail --version or man tail
Establish the command surface: man tail or tail --help
Start with a read-only probe: tail -n 10 file.txt

Intent Router

Load only the reference file needed for the active request.

references/install-and-setup.md — Installing tail (GNU, BSD) on macOS, Linux, Windows
references/cheatsheet.md — Common flags, line/byte counts, follow mode, multiple files
references/advanced-usage.md — GNU vs BSD differences, log rotation handling, large files, performance
references/troubleshooting.md — Follow mode issues, file rotation, encoding, exit codes

Core Workflow

Verify tail version and variant (GNU vs BSD): tail --version or man tail
Specify count explicitly: -n <N> for lines or -c <N> for bytes
Use -F for logs (follows by filename, survives rotation)
Use -f for regular files (follows by file descriptor)
Set bounded startup context before follow mode

Quick Command Reference

tail --version                          # Check version (GNU vs BSD)
tail -n 10 file.txt                    # Last 10 lines (explicit count)
tail -c 1024 file.bin                  # Last 1024 bytes (explicit count)
tail -n +10 file.txt                   # All lines from line 10 onward
tail -f app.log                        # Follow (append-only, not rotation)
tail -F /var/log/app.log               # Follow with rotation support
tail -n 50 -F app.log                  # Last 50 lines, then follow
tail -q -n 5 file1.txt file2.txt      # Last 5 lines, no headers
man tail                               # Full manual and options

Safety Notes

Area	Guardrail
Explicit counts	Always use `-n` or `-c` with explicit numbers; defaults (10 lines) may not match intent.
Log rotation	Use `-F` for logs that rotate; `-f` alone may lose updates when file is replaced.
Multiple files	Follow mode (`-f`) on multiple files prints clear headers; verify file source before processing.
GNU vs BSD	GNU supports `-n +N` (from line N); BSD uses same syntax but behavior may differ. Test on target platform.
Large files	tail seeks to end (efficient), but reads backward for line boundaries; very large files may be slow.
Incomplete lines	When using `-c`, output may end mid-line; subsequent processing may fail if expecting complete records.

Source Policy

Treat the installed tail behavior and man tail as runtime truth.
Use GNU Coreutils documentation (gnu.org/software/coreutils) for GNU-specific extensions.
Use BSD manual for BSD variant behavior differences.

Resource Index

scripts/install.sh — Install tail (GNU, BSD, or POSIX variant) on macOS or Linux.
scripts/install.ps1 — Install tail on Windows or any platform via PowerShell.