1 Introduction

An ID database is a binary file containing a list of file names, a list of tokens, and a sparse matrix indicating which tokens appear in which files.

With this database and some tools to query it (described in this manual), many text-searching tasks become simpler and faster. For example, you can list all files that reference a particular #include file throughout a huge source hierarchy, search for all the memos containing references to a project, or automatically invoke an editor on all files containing references to some function or variable. Anyone with a large software project to maintain, or a large set of text files to organize, can benefit from the ID utilities.

Although the name `ID' is short for `identifier', the ID utilities handle more than just identifiers; they also treat other kinds of tokens, most notably numeric constants, and the contents of certain character strings. Thus, this manual will use the word token as a term that is inclusive of identifiers, numbers and strings.

There are several programs in the ID utilities family:

mkid

scans files for tokens and builds the ID database file.

lid

queries the ID database for tokens, then reports matching file names or matching lines.

fid

lists all tokens recorded in the database for given files, or tokens common to two files.

fnid

matches the file names in the database, rather than the tokens.

xtokid

extracts raw tokens—helps with testing of new mkid scanners.

In addition, the ID utilities have historically provided several query programs which are specializations of lid:

gid

(alias for `lid -R grep') lists all lines containing the requested pattern.

eid

(alias for `lid -R edit') invokes an editor on all files containing the requested pattern, and if possible, initiates a text search for that pattern.

aid

(alias for `lid -ils') treats the requested pattern as a case-insensitive literal substring.

Please report bugs to `bug-idutils@gnu.org'. Remember to include the version number, machine architecture, input files, and any other information needed to reproduce the bug: your input, what you expected, what you got, and why it is wrong. Diffs are welcome, but please include a description of the problem as well, since this is sometimes difficult to infer. See Bugs.