dladdr(3X)                                                       dladdr(3X)

NAME
     dladdr - translate address to symbolic information

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

     #include <dlfcn.h>

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

DESCRIPTION
     dladdr() is one of a family of routines that give the user direct
     access to the dynamic linking facilities. These routines are made
     available via the library loaded when the option -ldl is passed to the
     link-editor.

     Note: These routines are available to dynamically-linked processes
     only.

     dladdr() determines if the specified address is located within one of
     the mapped objects that make up the current applications address
     space. An address is considered 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 run-time 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 Dlinfo structure must be preallocated by the user. The structure
     members are filled in by dladdr() based on the specified address. The
     Dlinfo structure includes the following members:

          const char    *dlifname;
          void          *dlifbase;
          const char    *dlisname;
          void          *dlisaddr;
          sizet         dlisize;
          int            dlibind;
          int            dlitype;

     Descriptions of these members appear below.

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

     dlifbase   Contains the base address of the containing object.

     dlisname   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.

     dlisaddr   Contains the actual address of the above symbol.



Page 1                       Reliant UNIX 5.44                Printed 11/98

dladdr(3X)                                                       dladdr(3X)

     dlisize    Contains the size in bytes of the above symbol.

     dlibind    Contains the binding attributes of the above symbol.

     dlitype    Contains the type of the above symbol.

RESULT
     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
     Dlinfo elements are filled.

NOTES
     The Dlinfo 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(3X)].

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

SEE ALSO
     ld(1), dlclose(3X), dlerror(3X), dlopen(3X), dlsym(3X).

     Chapter on "The C compilation system" in Guide to Tools for Program-
     ming in C.






























Page 2                       Reliant UNIX 5.44                Printed 11/98