2 .\" Copyright (c) 1998 John D. Polstra
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33 .Nd find the shared object containing a given address
39 .Fn dladdr "const void *addr" "Dl_info *info"
44 queries the dynamic linker for information about the shared object
45 containing the address
47 The information is returned in the structure specified by
49 The structure contains at least the following members:
50 .Bl -tag -width "XXXconst char *dli_fname"
51 .It Li "const char *dli_fname"
52 The pathname of the shared object containing the address.
53 .It Li "void *dli_fbase"
54 The base address at which the shared object is mapped into the
55 address space of the calling process.
56 .It Li "const char *dli_sname"
57 The name of the nearest run-time symbol with a value less than or
60 When possible, the symbol name is returned as it would appear in C
63 If no symbol with a suitable value is found, both this field and
67 .It Li "void *dli_saddr"
68 The value of the symbol returned in
75 is available only in dynamically linked programs.
77 If a mapped shared object containing
82 In that case, a message detailing the failure can be retrieved by
86 On success, a non-zero value is returned.
93 function first appeared in the Solaris operating system.
95 This implementation is bug-compatible with the Solaris
97 In particular, the following bugs are present:
102 lies in the main executable rather than in a shared library, the
106 The pathname is taken directly from
108 of the calling process.
109 When executing a program specified by its
110 full pathname, most shells set
113 But this is not required of shells or guaranteed
114 by the operating system.
122 is a global function, its value may be an unpleasant surprise.
124 dynamically linked programs, the address of a global function is
125 considered to point to its program linkage table entry, rather than to
126 the entry point of the function itself.
127 This causes most global
128 functions to appear to be defined within the main executable, rather
129 than in the shared libraries where the actual code resides.
131 Returning 0 as an indication of failure goes against long-standing