[insert project logo here (125x200px max)] Navigator Home Downloads Documentation Research News Forums Project Summary CVS repository Mailinglists Help Announcement Developer Please report any errors or ommissions you find to our `Help' mailinglist, or post a message in the Forums. Copyright and Licensing Information Snap is (c) Jonathan T. Moore, 1999-2002 and licensed under the GNU General Public License (GPL). All other parts of Splash are (c) Willem de Bruijn, 2002-2003 and licensed under the BSD Open Source License. All sourcecode is made publicly available. Acknowledgement Splash and the Splash website are hosted by SourceForge.net

Splash - Documentation SNMP Plus a Lightweight API for SNAP Handling             snap-1.1-wjdb/lib/snap_svc_library_handler.c Go to the documentation of this file. /* snap service handler library handler source file (c) 2003 Willem de Bruijn all code falls under the BSD License */ /* dlopen() API programming tips (from http://www.linux.se/doc/HOWTO/Program-Library-HOWTO/dl-libraries.html) if a library exports a function named '_init' this is executed before dlopen(..) returns equally, '_fini' will be executed before dlclose(..) returns (if it exists) unfortunately, this behaviour is currently broken under Linux due to crt.o exporting the same symbols link the ELF object compiled using the dlopen() API againts libdl (add '-ldl' to your gcc statements) optionally (and preferably ;) you can also add the '-Wl,--export-dynamic' statement check the exports from a library using 'nm' (man page under nm(1)) */ #include <stdlib.h> #include <dlfcn.h> /* for the dlopen() API*/ #include <dirent.h> /* for scandir() */ #include <string.h> #include <errno.h> #include "d_printf.h" #include "snap_svc_library_handler.h" /* LOW LEVEL dlopen() API FUNCTIONS */ int snap_svc_logerrors(int dLineNo){ char* strError; int dErrorCount = 0; do { strError = dlerror(); if (strError){ d_printf(20,"\nsnap_svc : encountered dlopen API error at line %d: %s\n", dLineNo, strError); dErrorCount++; } } while (strError); return dErrorCount; } /* open a library, return OK ? false : true */ int snap_svc_open(void** hDll, char* strLib){ *hDll = dlopen(strLib,RTLD_NOW); if (! *hDll) return snap_svc_logerrors(__LINE__); else return 0; } /* bind a library function to a pointer */ int snap_svc_bind(void* hDll, char* strFunc, void** hFunc){ int dErrorsOccurred = 0; if (!hDll){ d_printf(20,"snap_svc : trying to bind from closed library at %d\n", __LINE__); return -1; } *hFunc = dlsym(hDll,strFunc); if (!hFunc) /* it is possible to retrieve NULL handles therefore we test for errors before exiting with a failure */ dErrorsOccurred = snap_svc_logerrors(__LINE__); return dErrorsOccurred; } /* close a library */ int snap_svc_close(void** hDll){ int dErrorsOccurred = 0; if (! *hDll) d_printf(20,"snap_svc : trying to close a library with a NULL handle at %d\n", __LINE__); if (dlclose(*hDll)) dErrorsOccurred = snap_svc_logerrors(__LINE__); *hDll = NULL; return dErrorsOccurred; } /* DERIVED FUNCTIONS */ /* helper functions for snap_svc_openmultiple */ int snap_svc_openmultiple_selector_empty(const struct dirent* curentry){ return (!strncmp(".so",&curentry->d_name[_D_EXACT_NAMLEN(curentry) - 3],3)); } int snap_svc_openmultiple_selector_snapsvc(const struct dirent* curentry){ /* the macro below uses different calculation methods based on the underlying OS */ if (_D_EXACT_NAMLEN(curentry) <= (12 + 3) ) /* shorter than or equal to strncmp item1 + ".so" ? fail */ return 0; else if (strncmp(".so",&curentry->d_name[_D_EXACT_NAMLEN(curentry) - 3],3)) return 0; else{ if (!strncmp("libsnap_svc_", curentry->d_name, 12)) d_printf(100,"\nsnap_svc : found a library: %s\n",curentry->d_name); return (!strncmp("libsnap_svc_", curentry->d_name, 12)); } } /* open all libraries in directory strDir that are accepted by the fileselector function returns the number of succesfully opened libraries, -1 on error */ int snap_svc_openmultiple(void*** hDllList, char* strDir, snap_svc_fileselector thisSelector){ struct dirent** returnEntries; int dEntryCount, dCurEntry=0, dSuccessCount=0; if (*hDllList){ d_printf(50,"snap_svc : warning : received a non NULL pointer in snap_svc_openmultiple at lineno %d\n", __LINE__); *hDllList = NULL; } dEntryCount = scandir(strDir, &returnEntries, thisSelector, alphasort); if (dEntryCount == -1){ d_printf(20,"snap_svc : an error occurred while scanning a directory at lineno %d : dir %s error %d",__LINE__, strDir, errno); return -1; } if (dEntryCount == 0) return 0; /* try to load the files */ *hDllList = (void**) calloc( (dEntryCount + 1) , sizeof(void*) ); for (; dCurEntry < dEntryCount; dCurEntry++){ if (! snap_svc_open(&(*hDllList)[dCurEntry], returnEntries[dCurEntry]->d_name) ) dSuccessCount++; if ((int) (*hDllList)[dCurEntry] == -1) d_printf(20,"snap_svc : warning : a libpointer to -1 was returned at line %d, this will break memory mgmt\n",__LINE__); free (returnEntries[dCurEntry]); } (int) ((*hDllList)[dEntryCount]) = -1; free (returnEntries); return dSuccessCount; } /* try to close multiple libraries */ int snap_svc_closemultiple(void*** hDllList){ int dCurEntry = 0, dErrorCount = 0; if (!*hDllList) return 0; while (((int) ((*hDllList)[dCurEntry])) != -1){ /* while not at end of queue */ if ( (*hDllList)[dCurEntry] ){ dErrorCount = snap_svc_close(&(*hDllList)[dCurEntry]) % 1; (*hDllList)[dCurEntry] = NULL; } dCurEntry++; } free (*hDllList); hDllList = NULL; return dErrorCount; }