Added description of the library-search feature related flags.

doc/scsh-manual/running.tex

@@ -208,6 +208,26 @@ where
                         & Load file into current package. \\
 
                         
+                        
+                        & \ex{-ll} \var{module-file-name} 
+                        & As in -lm, but search the library path list.\\
+                        & \ex{+lp}  \var{dir}
+                        & Add dir to front of library path list.\\
+                        & \ex{lp+}  \var{dir}
+                        & Add dir to end of library path list.\\
+                        & \ex{+lpe} \var{dir}
+                        & +lp, with env var and \~user expansion.\\
+                        & \ex{lpe+} \var{dir}
+                        & lp+, with env var and \~user expansion.\\
+                        & \ex{+lpsd}                    
+                        & Add script-file's dir to front of path list.\\
+                        & \ex{lpsd+}                    
+                        & Add script-file's dir to end of path list.\\
+                        & \ex{-lp-clear}                
+                        & Clear library path list to ().\\
+                        & \ex{-lp-default}              
+                        & Reset library path list to system default.\\
+                        
                         & \ex{-dm} & Do script module. \\
                         & \ex{-ds} & Do script. \\
 \\
@@ -366,6 +386,77 @@ The following switches and end options are defined:
 
     This switch is provided to make it easy to write shell scripts in the
     {\scm} module language.
+
+\Item{-ll \var{modul-file-name}}
+    Load library module into config package.
+    This is just like the -lm switch, except that it searches the
+    library-directory path list for the file to load.
+    
+    Specifically, it means: search through the
+    \textit{library-directories} list of directories looking for a
+    module file of the given name, and load it in.
+    
+    The \textit{library-directories} list defaults to
+    \texttt{("/usr/local/lib/scsh/modules/")}. It will be
+    installation-dependent in a later version of scsh.
+    
+    If the environment variable \texttt{\$SCSH\_LIB\_DIRS} is set, it is
+    used to determine the library search path. The value of this
+    environment variable treated as a sequence of s-expressions, which
+    are ``read'' from the string:
+    
+    \begin{itemize}
+      \item  A string is treated as a directory.
+      \item \sharpf{} is replaced with the default list of directories.
+    \end{itemize}
+
+    A \texttt{SCSH\_LIB\_DIRS} assignment of this form
+    \begin{small}
+\begin{verbatim}
+SCSH_LIB_DIRS='"." "/usr/contrib/lib/scsh/" #f "/home/shivers/lib/scsh"'
+\end{verbatim}
+    \end{small}
+    would produce this list of strings for the
+    \textit{library-directories} list:
+    \begin{verbatim}
+          ("." "/usr/contrib/lib/scsh/" 
+          "/usr/local/lib/scsh/modules/" 
+          "/home/shivers/lib/scsh")
+    \end{verbatim}
+    
+    When searching for a directory containing a given library module,
+    nonexistent or read-protected directories are silently ignored; it
+    is not an error to have them in the \textit{library-directories}
+    list.
+    
+    It is a startup error if reading the \texttt{\$SCSH\_LIB\_DIRS}
+    env var causes a read error, or produces a value that isn't a
+    string or \sharpf.  
+
+    Directory search can be recursive. A directory name that ends
+    with a slash is recursively searched.
+
+\Item{+lp \var{lib-dir},lp+ \var{lib-dir}}
+    Add directory \var{lib-dir} to the beginning or end of the
+    \textit{library-directories} path list, respectively.
+
+    \var{lib-dir} is a single directory. It is not split at colons or
+    otherwise processed.
+
+\Item{+lpe, lpe+}
+    As above, except that \~ home-directory syntax and environment
+    variables are expanded out.
+     
+\Item{-lp-clear, -lp-default}
+    Set the \textit{library-directories} path list to the empty list and
+    the system default, respectively.
+        
+    These two switches are useful if you would like to protect your
+    script from influence by the \texttt{\$SCSH\_LIB\_PATH} variable.
+
+    In these cases, the \texttt{SCSH\_LIB\_PATH} environment variable is never
+    even parsed, so a bogus value will not affect the script's
+    execution at all.
 \end{itemize}
 
 \subsection{The meta argument}
@@ -802,3 +893,7 @@ so \ex{scsh.image} should have a \ex{\#!} trigger of the following form:
 -o /usr/local/lib/scsh/scshvm -i
 {\ldots} \textnormal{\emph{heap image goes here}} \ldots\end{code}
 
+%%% Local Variables: 
+%%% mode: latex
+%%% TeX-master: "man"
+%%% End: