lumiera_/src/lib/searchpath.cpp

105 lines
3.4 KiB
C++

/*
Searchpath - helpers for searching directory lists and locating modules
Copyright (C) Lumiera.org
2011, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
#include "lib/error.hpp"
#include "lib/searchpath.hpp"
#include "lib/symbol.hpp"
/** how to retrieve the absolute path of the currently running executable
* on a Linux system: read the link provided by the kernel through /proc
*/
#define GET_PATH_TO_EXECUTABLE "/proc/self/exe"
namespace lib {
LUMIERA_ERROR_DEFINE (FILE_NOT_DIRECTORY, "path element points at a file instead of a directory");
const regex SearchPathSplitter::EXTRACT_PATHSPEC ("[^:]+");
/** @internal helper to figure out the installation directory,
* as given by the absolute path of the currently executing program
* @warning this is Linux specific code */
string
findExePath()
{
static string buff(lib::STRING_MAX_RELEVANT+1, '\0' );
if (!buff[0])
{
ssize_t chars_read = readlink (GET_PATH_TO_EXECUTABLE, &buff[0], lib::STRING_MAX_RELEVANT);
if (0 > chars_read || chars_read == ssize_t(lib::STRING_MAX_RELEVANT))
throw error::Fatal ("unable to discover path of running executable");
buff.resize(chars_read);
}
return buff;
}
/** @internal helper to replace all $ORIGIN prefixes in a given string
* by the directory holding the current executable
* @note also picks ORIGIN, $ORIGIN/, ORIGIN/
*/
string
replaceMagicLinkerTokens (string const& src)
{
static const regex PICK_ORIGIN_TOKEN ("\\$?ORIGIN/?");
static const string expandedOriginDir
= fsys::path (findExePath()).parent_path().string() + "/"; ///////////TICKET #896
return boost::regex_replace(src, PICK_ORIGIN_TOKEN, expandedOriginDir);
}
string
resolveModulePath (fsys::path moduleName, string searchPath)
{
fsys::path modulePathName (moduleName);
SearchPathSplitter searchLocation(searchPath); ///////////TICKET #896
while (!fsys::exists (modulePathName))
{
// try / continue search path
if (searchLocation.isValid())
modulePathName = fsys::path() / searchLocation.next() / moduleName;
else
throw error::Config ("Module \""+moduleName.string()+"\" not found" /////TICKET #896
+ (searchPath.empty()? ".":" in search path: "+searchPath));
}
INFO (config, "found module %s", modulePathName.string().c_str());
return modulePathName.string(); ///////////TICKET #896
}
} // namespace lib