GNU soelim is a preprocessor for the groff(7) document formatting system. soelim works as a filter to
eliminate source requests in roff(7) input files; that is, it replaces lines of the form “.soincluded-file” within each text input-file with the contents of included-file, recursively. By default, it writes
lf requests as well to record the name and line number of each input-file and included-file, so that any
diagnostics produced by later processing can be accurately traced to the original input. Options allow
this information to be suppressed (-r) or supplied in TeX comments instead (-t). In the absence of
input-file arguments, soelim reads the standard input stream. Output is written to the standard output
stream.
If the name of a macro-file contains a backslash, use \\ or \e to embed it. To embed a space, write “\ ”
(backslash followed by a space). Any other escape sequence in macro-file, including “\[rs]”, prevents
soelim from replacing the source request.
The dot must be at the beginning of a line and must be followed by “so” without intervening spaces or
tabs for soelim to handle it. This convention allows source requests to be “protected” from processing
by soelim, for instance as part of macro definitions or “if” requests.
There must also be at least one space between “so” and its macro-file argument. The -C option overrides
this requirement.
The foregoing is the limit of soelim's understanding of the roff language; it does not, for example,
replace the input line
.if 1 .so otherfile
with the contents of otherfile. With its -r option, therefore, soelim can be used to process text files
in general, to flatten a tree of input documents.
soelim was designed to handle situations where the target of a roff source request requires a
preprocessor such as eqn(1), pic(1), refer(1), or tbl(1). The usual processing sequence of groff(1) is
as follows.
input sourced
file file
⎪ ⎪
↓ ↓
preprocessor ⎯→ troff ⎯→ postprocessor
⎪
↓
output
file
That is, files sourced with “so” are normally read only by the formatter, troff. soelim is not required
for troff to source files.
If a file to be sourced should also be preprocessed, it must already be read before the input file passes
through the preprocessor. soelim, normally invoked via groff's -s option, handles this.
input
file
⎪
↓
soelim ⎯→ preprocessor ⎯→ troff ⎯→ postprocessor
↑ ⎪
⎪ ↓
sourced output
file file