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)