lid.idutils

lid [options] [pattern]

lid queries an ID database to find tokens matching a specified pattern. Part of GNU idutils, it searches a pre-built token database to quickly locate identifiers across source files.An ID database must first be built using the mkid command. The database indexes all tokens (identifiers, keywords, strings) found in source files, enabling fast lookups without rescanning the entire codebase.Patterns are interpreted flexibly: if a pattern contains regex metacharacters, lid performs a regex substring search; otherwise it conducts a literal word search. When no pattern is given, all database entries are listed.

-f _filename_

Specify which ID database file to read

Perform case-insensitive pattern matching

Treat the pattern as a literal string (no regex)

Force regular expression pattern matching

Match whole words only (non-substring search)

Perform substring search

Control output format: token, pattern, or none

Control result type: filenames, grep (show lines), edit (open in editor), or none

Match tokens by occurrence frequency (e.g., 1 for tokens appearing once)

Requires a pre-built ID database created with mkid. The database must be regenerated after source files change to reflect current content. By default, lid searches for a file named ID in the current directory or its parents.

The lid command is part of GNU idutils, originally written by Greg McGary. The idutils package has been maintained as part of the GNU project since the early 1990s, providing efficient source code indexing and searching capabilities.

mkid(1), grep(1)