Copyright (c) 2003 Alexey Zelkin <phantom@FreeBSD.org>
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$FreeBSD: head/lib/libc/gen/dlinfo.3 110852 2003-02-14 10:07:43Z phantom $
.Dd February 14, 2003 .Os .Dt DLINFO 3 .Sh NAME .Nm dlinfo .Nd information about dynamically loaded object .Sh LIBRARY .Lb libc .Sh SYNOPSIS n link.h n dlfcn.h .Ft int .Fn dlinfo "void * __restrict handle" "int request" "void * __restrict p" .Sh DESCRIPTION The .Fn dlinfo function provides information about dynamically loaded object. The action taken by .Fn dlinfo and exact meaning and type of .Fa p argument depend on value of the .Fa request argument provided by caller.
p A .Fa handle argument is either the value returned from a .Fn dlopen function call or special handle .Dv RTLD_SELF . If handle is the value returned from .Fn dlopen call, the information returned by the .Fn dlinfo function is pertains the specified object. If handle is the special handle .Dv RTLD_SELF , the information returned pertains to the caller itself.
p The following are possible values for .Fa request argument to be passed into .Fn dlinfo : l -tag -width Ds t RTLD_DI_LINKMAP Retrieve the Link_map (or .Ft struct link_map ) structure pointer for .Fa handle specified. On successful return the .Fa p argument is filled with pointer to Link_map structure .Ft ( Link_map **p ) describing shared object specified by .Fa handle argument. .Ft Link_map stuctures are maintained as double-linked list by .Xr ld.so 1 in same order as .Fn dlopen and .Fn dlclose are called. See .Sx EXAMPLES (Example 1) t RTLD_DI_SERINFO Retrieve the library search paths associated with given .Fa handle argument. The .Fa p argument should point to .Ft Dl_serinfo structure buffer .Fa ( Dl_serinfo *p ) . .Ft Dl_serinfo structure must be initialized first with a .Dv RTLD_DI_SERINFOSIZE request.
p The returned .Ft Dl_serinfo structure contains .Dv dls_cnt .Ft Dl_serpath entries. Each entry's .Dv dlp_name field points to the search path. The corresponding .Dv dlp_info field contains one of more flags indicating the origin of the path (see the .Dv LA_SER_* flags defined in <link.h> header file.) See .Sx EXAMPLES (Example 2) for usage example. t RTLD_DI_SERINFOSIZE Initialize a .Ft Dl_serinfo structure for use in a .Dv RTLD_DI_SERINFO request. Both the .Dv dls_cnt and .Dv dls_size fields are returned to indicate the number of search paths applicable to the handle, and the total size of a .Ft Dl_serinfo buffer required to hold .Dv dls_cnt .Ft Dl_serpath entries and the associated search path strings. See .Sx EXAMPLES (Example 2) for usage example. t RTLD_DI_ORIGIN Retrieve the origin of the dynamic object associated with the handle. On successful return .Fa p argument is filled with .Ft char pointer .Ft ( char *p ) . .El .Sh EXAMPLES To be continued .Sh RETURN VALUES .Fn dlinfo returns 0 on success, or -1 if error occured. Whenever an error has been detected, a message detailing it can be retrieved via a call to .Fn dlerror . .Sh SEE ALSO .Xr rtld 1 , .Xr dladdr 3 , .Xr dlopen 3 , .Xr dlsym 3 .Sh HISTORY The .Fn dlinfo function first appeared in the Solaris operating system. In .Fx it first appeared in .Fx 4.8 . .Sh AUTHORS The .Fn dlinfo function was originally written by .An Alexey Zelkin .Aq phantom@FreeBSD.org and later extended and improved by .An Alexander Kabaev .Aq kan@FreeBSD.org .
p The manual page for this function was written by .An Alexey Zelkin .Aq phantom@FreeBSD.org .