Function: _def_sopath
Class: default
Section: default
C-Name: sd_sopath
Prototype:
Help:
Doc: this is a list of directories, separated by colons ':'
 (semicolons ';' in the DOS world, since colons are preempted for drive names).
 When asked to \tet{install} an external symbol from a shared library whose
 name is not given by an absolute path (does not start with \kbd{/}, \kbd{./}
 or \kbd{../}), \kbd{gp} will look for it in these directories, in the order
 they were written in \kbd{sopath}. Here, as usual, \kbd{.} means the current
 directory, and \kbd{..} its immediate parent. Environment expansion is
 performed.

 The default value is \kbd{""}, corresponding to an empty list of
 directories: \tet{install} will use the library name as input (and look in
 the current directory if the name is not an absolute path).
