zsoelim

soelim [-CIV] [-I DIR] [file ...]

-C
    Recognizes .so even if it is not followed by a space or newline character. This provides more flexibility in how the request can be written.

-I DIR
    Adds DIR to the list of directories to search for files specified in .so requests. Multiple -I options can be used. The search order is the current directory first, then the specified DIRs in the order they appear.

-V
    Prints the version information of the soelim utility to standard output.

The soelim command (often confused with 'zsoelim') serves as a pre-processor for roff (groff/nroff/troff) input files. Its primary function is to expand and include the content of other files specified by the .so request. When soelim encounters a line like .so filename, it replaces that line with the entire content of filename. This mechanism is crucial for modularizing roff source documents, allowing common definitions, macros, or text blocks to be reused across multiple files, similar to the #include directive in C programming. It's frequently used in the context of manual pages (man pages) to include standard macro sets.

soelim only processes .so requests and does not interpret any other roff macros or commands. It is a simple pre-processor. The functionality of soelim is often implicitly handled or integrated within modern groff tools, making direct manual invocation less common for typical users.

The command 'zsoelim' is not a standard or recognized Linux command. It is highly probable that it is a typographical error for 'soelim'. The information provided above pertains to the 'soelim' command, which is a legitimate utility within the groff suite for processing .so requests in roff input.

soelim has been an integral part of the troff and nroff text formatting systems since their early days on Unix, providing a fundamental mechanism for including external files. It became part of the GNU groff (GNU roff) project, which is a free implementation of the troff text-formatting system. Its role in enabling modularity for documents, especially for system manual pages, has remained consistent throughout its development.

groff(1), nroff(1), troff(1), man(1)