.Dd September 24, 2004 .Os .Dt DLADDR 3 .Sh NAME .Nm dladdr .Nd find the image containing a given address .Sh SYNOPSIS .In dlfcn.h .Ft int .Fn dladdr "const void* addr" "Dl_info* info" .Sh DESCRIPTION The .Fn dladdr function queries dyld (the dynamic linker) for information about the image containing the address .Fa addr . The information is returned in the structure specified by .Fa info . The structure contains at least the following members: .Bl -tag -width "XXXconst char *dli_fname" .It Li "const char* dli_fname" The pathname of the shared object containing the address. .It Li "void* dli_fbase" The base address (mach_header) at which the image is mapped into the address space of the calling process. .It Li "const char* dli_sname" The name of the nearest run-time symbol with a value less than or equal to .Fa addr . .It Li "void* dli_saddr" The value of the symbol returned in .Li dli_sname . .El .Pp The .Fn dladdr function is available only in dynamically linked programs. .Sh ERRORS If an image containing .Fa addr cannot be found, .Fn dladdr returns 0. On success, a non-zero value is returned. .Pp If the image containing .Fa addr is found, but no nearest symbol was found, the dli_sname and dli_saddr fields are set to NULL. .Sh SEE ALSO .Xr dyld 3 , .Xr dlopen 3 .Sh HISTORY The .Fn dladdr function first appeared in the Solaris operating system. .Sh AUTHORS Mac OS X 10.3 incorporated the dlcompat package written by Jorge Acereda <jacereda@users.sourceforge.net> and Peter O'Gorman <ogorman@users.sourceforge.net>. .Pp In Mac OS X 10.4, dlopen was rewritten to be a native part of dyld. .Pp This man page was borrowed from FreeBSD and modified. .Sh BUGS This implementation is almost bug-compatible with the Solaris implementation. The following bugs are present: .Bl -bullet .It Returning 0 as an indication of failure goes against long-standing Unix tradition. .El