Display text files with syntax highlighting and line numbers.

show-cli is a small, fast CLI written in Go that:

• Highlights source code via Chroma
• Adds locale-aware line numbers (UTF‑8 │ or ASCII |)
• Supports themes and explicit filetype selection
• Provides shell completions for Bash/Zsh/Fish
• Offers a debug mode to show detected file type metadata

• Syntax highlighting with Chroma (auto-detect by path/content, or override with --filetype).
• Terminal formatter fallback: prefers 24-bit (terminal16m), then 256-color, then plain.
• Themes: choose from Chroma styles; defaults to onedark.
• Line numbers: fixed-width prefixes with locale-dependent separator.
• Deterministic output toggles for tests via environment variables.

Prerequisites: Go 1.22+

Build from source:

make build
# or
go build -o bin/show ./cmd/show

Run:

bin/show --help

show <path>

• -h, --help: show help
• -v, --version: print version
• -d, --debug: print debug file type metadata (header + footer)
• -t, --filetype <type>: force syntax highlighting file type (lexer alias)
• --theme <name>: set syntax highlighting theme (default: onedark)
• --list-file-types: print supported file type aliases (one per line)
• --list-themes: print supported syntax highlighting themes (one per line)
• --install-completion <bash|zsh|fish>: print shell completion script

These are Chroma lexer aliases (lowercase). For the full, up-to-date list:

bin/show --list-file-types

Common aliases include:

• go, python, javascript, typescript
• yaml, json, toml, ini
• bash, fish, zsh, powershell
• markdown, rst, html, css
• sql, dockerfile, make, terraform, hcl
• php, ruby, java, kotlin, swift
• c, cpp, rust

show README.md
show --debug README.md
show --filetype go main.txt
show --theme github-dark README.md
show --list-file-types
show --list-themes
NO_COLOR=1 show README.md

show --install-completion bash > /etc/bash_completion.d/show

show --install-completion zsh > ${fpath[1]}/_show

show --install-completion fish > ~/.config/fish/completions/show.fish

• NO_COLOR=1: disable colored line-number prefixes (syntax highlighting may still emit ANSI).
• LC_ALL, LC_CTYPE, LANG: if any indicates UTF‑8, uses │ as the line separator; otherwise uses |.

Inject build metadata with ldflags:

go build -ldflags "-X main.version=v0.1.0 -X main.commit=$(git rev-parse --short HEAD) -X main.date=$(date -u +%Y-%m-%dT%H:%M:%SZ)" -o bin/show ./cmd/show

Runtime flags:

bin/show --version

Run locally:

go run ./cmd/show --help

Run tests:

go test ./...

Contributions are welcome! Please:

• Keep changes focused and well-tested (go test ./...).
• Follow existing patterns (dependency injection via show.Deps, CLI surface in internal/cli, core logic in internal/show).
• Discuss significant changes via an issue or PR description.
• Use Conventional Commit message as possible

We’re seeking contributors to help with the following:

• Documentation: refine and expand this README and usage examples.
• ~/.config support: load default settings (e.g., theme, line number options) from a user config (proposed path: ~/.config/show/config.yaml).
• Cross-platform binaries: build and publish release artifacts for Linux, macOS, and Windows (e.g., via GoReleaser).
• Homebrew packaging: submit and maintain a formula (tap or Homebrew/core) once release binaries exist.
• Bug tracking: file and triage issues with clear reproduction steps; propose fixes via small PRs.
• CI/CD: set up pipelines for tests, lint, and build (e.g., GitHub Actions), including release workflows.

If you’re interested, please open an issue describing what you’d like to tackle, and we can coordinate on scope and approach.

• CLI framework: github.com/urfave/cli/v2
• Syntax highlighting: github.com/alecthomas/chroma/v2
• Conventional Commit: https://www.conventionalcommits.org/en/v1.0.0/