code-search

Code Search

CLI search for source code. Pick the modality by what you know.

This skill is portable across GitHub Copilot, APM, and Claude Code; keep the references/ folder next to SKILL.md when copying it into a Copilot skill location.

Task	Use	Reference
Text / regex in code	rg	ripgrep
Find files by name/path	fd	fd
Structural / syntax-aware search	sg (ast-grep)	ast-grep
Security/lint rule packs, taint	semgrep	semgrep
Symbol defs / refs / call hierarchy	LSP · global · ctags	code-intelligence
When/why code changed	git log -S/-G/-L	git-history
Structural search-and-replace	comby, sg --rewrite	comby
Size / complexity by language	tokei, scc	metrics

Decision flow: text → rg | structural → sg | symbol defs/refs → LSP/global | rule packs → semgrep | filenames → fd | change history → git pickaxe | rewrite → comby | LOC → tokei.

Best practices

1. Start narrow — scope by type (rg -t py, sg --lang ts, fd -e go), restrict dirs, and count first (rg -c pattern | wc -l) before reading.
2. Exclude noise — rg -g '!vendor/' -g '!*.lock', fd -E node_modules.
3. Batch independent queries — union patterns (rg -e P1 -e P2) in one walk, or issue distinct searches as parallel tool calls. Never sequential &&.
4. rg -t ts includes .tsx; fd -e ts does NOT — use fd -e ts -e tsx.
5. For cross-modality strategy (semantic/graph, hybrid rerank), see the retrieval-strategy skill or invoke the retrieval-strategist agent.
6. Prefer rtk when installed — prefix the rtk-wrapped tools (rtk rg …, rtk git log …) for 60–90% smaller output; other tools run directly and rtk rg -c/-l stay raw (pipe-safe). See rtk.

For non-code corpora (JSON/YAML, CSV/Parquet, PDFs/Office), use the data-and-docs-search skill.