NAME

       ldd - print shared object dependencies

SYNOPSIS

       ldd [option]... file...

DESCRIPTION

       ldd  prints  the shared objects (shared libraries) required by each program or shared object specified on
       the command line.  An example of its use and output  (using  sed(1)  to  trim  leading  white  space  for
       readability in this page) is the following:

           $ ldd /bin/ls | sed 's/^ */    /'
               linux-vdso.so.1 (0x00007ffcc3563000)
               libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f87e5459000)
               libcap.so.2 => /lib64/libcap.so.2 (0x00007f87e5254000)
               libc.so.6 => /lib64/libc.so.6 (0x00007f87e4e92000)
               libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f87e4c22000)
               libdl.so.2 => /lib64/libdl.so.2 (0x00007f87e4a1e000)
               /lib64/ld-linux-x86-64.so.2 (0x00005574bf12e000)
               libattr.so.1 => /lib64/libattr.so.1 (0x00007f87e4817000)
               libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f87e45fa000)

       In   the   usual   case,   ldd   invokes   the   standard   dynamic   linker   (see  ld.so(8))  with  the
       LD_TRACE_LOADED_OBJECTS environment variable set to 1.  This causes the dynamic  linker  to  inspect  the
       program's  dynamic  dependencies,  and  find  (according to the rules described in ld.so(8)) and load the
       objects that satisfy those dependencies.  For each dependency, ldd displays the location of the  matching
       object  and  the  (hexadecimal)  address  at  which  it  is  loaded.  (The linux-vdso and ld-linux shared
       dependencies are special; see vdso(7) and ld.so(8).)

   Security
       Be aware that in some circumstances (e.g., where the program specifies an ELF interpreter other than  ld-
       linux.so),  some  versions  of  ldd  may  attempt  to  obtain the dependency information by attempting to
       directly execute the program, which may lead to  the  execution  of  whatever  code  is  defined  in  the
       program's  ELF  interpreter,  and  perhaps to execution of the program itself.  (In glibc versions before
       2.27, the upstream ldd implementation did this  for  example,  although  most  distributions  provided  a
       modified version that did not.)

       Thus,  you  should never employ ldd on an untrusted executable, since this may result in the execution of
       arbitrary code.  A safer alternative when dealing with untrusted executables is:

           $ objdump -p /path/to/program | grep NEEDED

       Note, however, that this alternative shows only the direct dependencies  of  the  executable,  while  ldd
       shows the entire dependency tree of the executable.

OPTIONS

       --version
              Print the version number of ldd.

       -v, --verbose
              Print all information, including, for example, symbol versioning information.

       -u, --unused
              Print unused direct dependencies.  (Since glibc 2.3.4.)

       -d, --data-relocs
              Perform relocations and report any missing objects (ELF only).

       -r, --function-relocs
              Perform  relocations  for  both  data  objects  and  functions,  and report any missing objects or
              functions (ELF only).

       --help Usage information.

BUGS

       ldd does not work on a.out shared libraries.

       ldd does not work with some extremely old a.out programs which were built before ldd support was added to
       the compiler releases.  If you use ldd on one of these programs, the program will  attempt  to  run  with
       argc = 0 and the results will be unpredictable.

SEE ALSO

       pldd(1), sprof(1), ld.so(8), ldconfig(8)

COLOPHON

       This  page  is  part  of  release  5.10  of  the  Linux man-pages project.  A description of the project,
       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       https://www.kernel.org/doc/man-pages/.

                                                   2019-03-06                                             LDD(1)