Files

SKILL.mdagentsreferences

Install

Install the containing plugin

/plugin install shared-skills@llm-skills

Invoke this skill after installation

/shared-skills:cat

Download cat-skill.zip

This skill is bundled inside shared-skills. Install the plugin once, then Claude Code can use any of its included skills. Browse the full plugin repository at github.com/alisonaquinas/llm-shared-skills.

SKILL.md

name: cat description: > Concatenate and display file contents with cat for reading files, combining multiple files, writing heredoc content, and feeding file data into pipelines. Use when the agent needs to print a file's contents to stdout, join several files into one, pipe a file into another command, or inspect a short file quickly.

cat

Concatenate files and print their contents to standard output.

Quick Start

Verify availability: cat --version (GNU) or man cat
Display a file: cat file.txt
Concatenate files: cat a.txt b.txt > combined.txt

Intent Router

references/cheatsheet.md — Display, concatenate, number lines, show non-printing characters, file writing via heredoc
references/advanced-usage.md — Combining with pipelines, heredoc patterns, binary file awareness, tac for reverse
references/troubleshooting.md — Binary content warnings, large file pitfalls, useless use of cat, encoding issues

Core Workflow

Use cat file for quick inspection of short files
Use cat a b c > out to concatenate multiple files in order
Pipe cat file | command only when the command does not accept a filename argument — many tools accept files directly, making cat unnecessary
Use cat -A or cat -v to reveal non-printing characters when diagnosing encoding or line-ending issues
Use cat -n to number lines for reference when discussing file content

Quick Command Reference

cat file.txt                        # Display file contents
cat a.txt b.txt                     # Concatenate and display two files
cat a.txt b.txt > combined.txt      # Concatenate into a new file
cat >> file.txt                     # Append stdin to a file (Ctrl-D to end)
cat -n file.txt                     # Number all output lines
cat -b file.txt                     # Number non-blank lines only
cat -A file.txt                     # Show all: mark tabs (^I), line ends ($)
cat -v file.txt                     # Show non-printing characters
cat -s file.txt                     # Squeeze multiple blank lines into one
tac file.txt                        # Print lines in reverse order
cat /dev/null > file.txt            # Truncate a file to zero bytes
man cat                             # Full manual

Safety Notes

Area	Guardrail
Overwrite with `>`	`cat a > b` overwrites `b` silently. Use `>>` to append. Confirm destination path before redirecting.
Binary files	`cat` will send raw binary bytes to the terminal, which can corrupt terminal state. Check with `file` first; use `xxd` or `hexdump` for binary inspection.
Large files	`cat` on a large file floods the terminal. Use `head`, `tail`, `less`, or `grep` for targeted inspection.
Useless use of cat	`cat file \| grep pattern` is better written as `grep pattern file`. Eliminating unnecessary `cat` reduces process overhead and clarifies intent.
Truncation via redirect	`cat /dev/null > file` or `> file` immediately truncates `file` to zero bytes. This is irreversible without a backup.

Source Policy

Treat man cat and cat --help as runtime truth. GNU and BSD cat share most flags.
Avoid "useless use of cat" — pass filenames directly to commands that accept them (grep, sort, wc, etc.).
Use less or bat for interactive browsing of files longer than a screenful.

cat