Dynamic Linking Library Functions                     dladdr(3DL)

NAME
     dladdr, dladdr1 - translate address to symbolic information

SYNOPSIS
     cc [ flag ... ] file... -ldl [ library ... ]
     #include <dlfcn.h>

     int dladdr(void *address, Dl_info *dlip);

     int dladdr1(void *address, Dl_info *dlip, void  **info,  int
     flags);

DESCRIPTION
     The dladdr() and dladdr1() functions determine if the speci-
     fied  address  is  located  within one of the mapped objects
     that make up the  current  applications  address  space.  An
     address  is deemed to fall within a mapped object when it is
     between the base address,  and  the  _end  address  of  that
     object.  If  a  mapped object fits this criteria, the symbol
     table made available to the runtime linker  is  searched  to
     locate  the  nearest  symbol  to the specified address.  The
     nearest symbol is one that has a value less than or equal to
     the required address.

     The Dl_info structure must be preallocated by the user.  The
     structure  members  are  filled  in by dladdr() based on the
     specified address. The Dl_info structure includes  the  fol-
     lowing members:

     const char *   dli_fname;
     void *         dli_fbase;
     const char *   dli_sname;
     void *         dli_saddr;

     Descriptions of these members appear below.

     dli_fname
           Contains a pointer to the filename of  the  containing
           object.

     dli_fbase
           Contains the base address of the containing object.

     dli_sname
           Contains a pointer to the symbol name nearest  to  the
           specified  address.  This  symbol  either has the same
           address,  or  is  the  nearest  symbol  with  a  lower
           address.

     dli_saddr
           Contains the actual address of the above symbol.

SunOS 5.8           Last change: 12 July 2000                   1

Dynamic Linking Library Functions                     dladdr(3DL)

     The dladdr1() function provides for addition information  to
     be returned as specified by the flags argument:

     RTLD_DL_SYMENT
           Obtain the ELF symbol table entry for the matched sym-
           bol.  The  info  argument  points  to a Sym pointer as
           defined in <sys/machelf.h> (Sym **info).

     RTLD_DL_LINKMAP
           Obtain the Link_map for the  matched  file.  The  info
           argument  points  to  a Link_map pointer as defined in
           <sys/link.h> (Link_map **info).

RETURN VALUES
     If the specified address  cannot  be  matched  to  a  mapped
     object,  a  0  is  returned. Otherwise, a non-zero return is
     made and the associated Dl_info elements are filled.

USAGE
     The dladdr() and dladdr1() functions are one of a family  of
     functions  that  give  the user direct access to the dynamic
     linking facilities (see Linker and Libraries Guide) and  are
     available to dynamically-linked processes only.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|

SEE ALSO
     ld(1), dlclose(3DL), dldump(3DL), dlerror(3DL), dlopen(3DL),
     dlsym(3DL), attributes(5)

     Linker and Libraries Guide

NOTES
     The Dl_info pointer elements point to addresses  within  the
     mapped  objects.  These  may  become  invalid if objects are
     removed prior to these elements being used (see dlclose()).

     If no symbol is found to  describe  the  specified  address,
     both the dli_sname and dli_saddr members are set to 0.

SunOS 5.8           Last change: 12 July 2000                   2