dlsym(3X)                      DG/UX R4.11MU05                     dlsym(3X)


NAME
       dlsym - get the address of a symbol in shared object

SYNOPSIS
       cc [flag ...] file ...  -ldl [library ...]

       #include <dlfcn.h>

       void *dlsym(void *handle, char *name);

DESCRIPTION
       dlsym allows a process to obtain the address of a symbol defined
       within a shared object previously opened by dlopen.  handle is a
       value returned by a call to dlopen; the corresponding shared object
       must not have been closed using dlclose.  name is the symbol's name
       as a character string.  dlsym will search for the named symbol in all
       shared objects loaded automatically as a result of loading the object
       referenced by handle [see dlopen(3X)].

EXAMPLES
       The following example shows how one can use dlopen and dlsym to
       access either function or data objects.  For simplicity, error
       checking has been omitted.

            void *handle;
            int i, *iptr;
            int (*fptr)(int);

            /* open the needed object */
            handle = dlopen("/usr/mydir/libx.so", RTLDLAZY);

            /* find address of function and data objects */
            fptr = (int (*)(int))dlsym(handle, "somefunction");

            iptr = (int *)dlsym(handle, "intobject");

            /* invoke function, passing value of integer as a parameter */

            i = (*fptr)(*iptr);

SEE ALSO
       dlerror(3X), dlopen(3X), dlsym(3X).

DIAGNOSTICS
       If handle does not refer to a valid object opened by dlopen, or if
       the named symbol cannot be found within any of the objects associated
       with handle, dlsym will return NULL.  More detailed diagnostic
       information will be available through dlerror.


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