Find Symbol Using ctags

This skill searches for symbol definitions (functions, structs, variables, classes) in the ctags indexes.

How It Works

The repository has two ctags indexes:

• Firmware (C code): inav/tags
• Configurator (JS code): inav-configurator/tags

Usage

When the user asks to find a symbol, search both indexes:

# Search firmware (C code)
grep "^SYMBOL_NAME\b" inav/tags | head -20

# Search configurator (JS code)
grep "^SYMBOL_NAME\b" inav-configurator/tags | head -20

Replace SYMBOL_NAME with the actual symbol to search for.

Parsing the Output

Each line in the tags file contains tab-separated fields:

1. Symbol name - The identifier being searched for
2. File path - Where the symbol is defined
3. Search pattern - Usually /^...$/ or line number
4. Extensions - Key-value pairs like kind:f, line:123, signature:(args)

Common kind values:

• f = function
• s = struct
• v = variable
• c = class
• m = member/method
• t = typedef
• d = #define/macro
• p = prototype

Reporting Results

Present the results in a clear format:

Found in firmware (C code):
- File: src/main/flight/pid.c:145
  Kind: function
  Signature: void pidController(timeUs_t currentTimeUs)

- File: src/main/flight/pid.h:23
  Kind: prototype

Found in configurator (JS code):
- File: js/controllers/configuration.js:89
  Kind: function

Use the format file_path:line_number to allow easy navigation.

Limitations

• JavaScript indexing is limited: ctags doesn't parse ES6+ features well

  • For JS code, Claude's built-in Grep tool often works better
  • Use Grep with pattern like: function.*symbolName or class symbolName

• C firmware indexing works well for functions, structs, variables, and macros

Regenerating Indexes

If source files have changed significantly and symbols aren't found:

# Firmware (C code)
cd inav
ctags -R --fields=+niazS --extras=+q --exclude=lib --exclude=build --exclude=tools --exclude=.git -f tags .

# Configurator (JS code)
cd inav-configurator
ctags -R --fields=+niazS --extras=+q --exclude=node_modules --exclude=.git --exclude=out --exclude=.vite --exclude=dist -f tags .

Examples

User asks: "Where is pidController defined?"

You should:

1. Run grep on both tags files with pattern ^pidController\b
2. Parse the results to extract file path and line number
3. Report in the format: src/main/flight/pid.c:145

User asks: "Find the navConfig struct"

You should:

1. Search for ^navConfig\b in both indexes
2. Look for entries with kind:s (struct) or kind:t (typedef)
3. Report all matches with file locations

Related Skills

• wiki-search - Search documentation for implementation guidance
• msp-protocol - Look up MSP commands and structures