lkbib

lkbib [OPTION]... KEY...
lkbib [OPTION]... -f FILE KEY...

KEY...
    One or more search terms or keys to look for in the BibTeX database.

-a
    Interpret multiple KEYs as a logical AND search; all keys must match. This overrides the default OR behavior.

-e
    Print the entire matching BibTeX entry, including all its fields, instead of just the key.

-f FILE
    Search exclusively in the specified BibTeX FILE instead of the directories listed in the BIBINPUTS environment variable.

-i
    Perform a case-insensitive search for KEYs or when searching within fields (with -s).

-o
    Interpret multiple KEYs as a logical OR search (this is the default behavior); an entry will be returned if any of the keys match.

-q
    Quiet mode; suppress warning messages and other non-essential output, showing only results or errors.

-r
    Interpret KEYs as regular expressions for more flexible and powerful pattern matching.

-s
    Search all fields of the BibTeX entries (e.g., author, title, year, abstract) instead of just the primary entry keys.

-t
    Force an exact match for the specified KEYs. This is often implied for key searches but can be particularly useful when combined with -s for precise field matching.

-u
    Print only unique matches, eliminating duplicate entries if an entry matches multiple search criteria or if the same entry is found in different files.

-v
    Verbose mode; print additional information, potentially including debugging output about the search process.

--help
    Display a brief help message showing usage and options, then exit.

--version
    Output version information about lkbib and exit.

lkbib is a command-line utility designed for searching BibTeX databases. It allows users to quickly locate bibliographic entries based on specified keys or by searching within all fields (like author, title, year). The command is particularly useful for LaTeX users who manage their references using BibTeX and need to quickly retrieve or verify entries.

By default, lkbib searches for exact matches of keys within .bib files specified by the BIBINPUTS environment variable or explicitly provided on the command line. It can return just the matching keys or the full BibTeX entries. Its functionality is relatively simple compared to more advanced bibliography managers, but it provides a lightweight and efficient way to query BibTeX data directly from the terminal, making it a valuable tool for scripting and quick lookups within a LaTeX workflow. It supports case-insensitive and regular expression searches, as well as logical AND/OR operations for multiple search terms.

The utility primarily relies on the BIBINPUTS environment variable to locate BibTeX files. If this variable is not set or does not point to the correct directories, lkbib may not find any entries unless files are explicitly specified with the -f option. Its searching capabilities, while functional, are basic and do not offer the advanced features of dedicated bibliography management software. It's often used for simple lookups rather than complex database management or formatting.

The lkbib command uses the BIBINPUTS environment variable to determine which directories to search for BibTeX (.bib) files. This variable should contain a colon-separated list of directories (on Unix-like systems) where your BibTeX databases are located. For example: export BIBINPUTS=/path/to/my/bibs:/another/path

Typically, lkbib is used to quickly verify if a BibTeX entry exists or to retrieve a full entry for inclusion in a .tex document. For example, lkbib -e specific_key will print the entire entry associated with 'specific_key' to standard output, which can then be piped or redirected for further use. It can also be used to quickly check for authors or titles: lkbib -s 'Knuth, Donald'.

lkbib is part of the TeX Live distribution, a comprehensive TeX system. Its development dates back to the early days of TeX and LaTeX, reflecting the need for command-line tools to manage bibliographic data within the academic and publishing workflows common with TeX. It has been maintained as a stable utility within the TeX Live project, serving its niche function of quick BibTeX database lookups and remaining relevant for command-line driven LaTeX users.

bibtex(1), latex(1), tex(1), grep(1)