unix/SysLibrary.cpp

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/******************************************************************************/
/* REXX Shared runtime                                                        */
/*                                                                            */
/* Unix implementation of the SysLibrary                                      */
/*                                                                            */
/******************************************************************************/
 
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
 
#include "SysLibrary.hpp"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <dlfcn.h>
 
 
#define MAX_LIBRARY_NAME_LENGTH 250
#define LIBARY_NAME_BUFFER_LENGTH (MAX_LIBRARY_NAME_LENGTH + sizeof("/usr/lib/lib") + sizeof(ORX_SHARED_LIBRARY_EXT))
 
SysLibrary::SysLibrary()
{
    libraryHandle = NULL;
}
 
 
void * SysLibrary::getProcedure(
  const char *name)                      /* required procedure name           */
/******************************************************************************/
/* Function:  Resolve a named procedure in a library                          */
/******************************************************************************/
{
    return dlsym(libraryHandle, name);
}
 
 
bool SysLibrary::load(
    const char *name)                    /* required library name             */
/******************************************************************************/
/* Function:  Load a named library, returning success/failure flag            */
/******************************************************************************/
{
    char nameBuffer[LIBARY_NAME_BUFFER_LENGTH];
 
    if (strlen(name) > MAX_LIBRARY_NAME_LENGTH)
    {
        return false;
    }
 
    snprintf(nameBuffer, sizeof nameBuffer, "lib%s%s", name, ORX_SHARED_LIBRARY_EXT);
    // try loading directly
    libraryHandle = dlopen(nameBuffer, RTLD_LAZY);
    // if not found, then try from /usr/lib
    if (libraryHandle == NULL)
    {
        snprintf(nameBuffer, sizeof nameBuffer, "/usr/lib/lib%s%s", name, ORX_SHARED_LIBRARY_EXT);
        libraryHandle = dlopen(nameBuffer, RTLD_LAZY);
        // still can't find it?
        if (libraryHandle == NULL)
        {
            return false;
        }
    }
    return true;     // loaded successfully
}
 
 
/**
 * Free a loaded library if the library is still loaded.
 *
 * @return True if we unloaded ok, false otherwise.
 */
bool SysLibrary::unload()
{
    if (libraryHandle != NULL)
    {
        dlclose(libraryHandle);
        return true;
    }
    return false;
}