ldd - print shared object dependencies
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
dependencies are special; see vdso(7) and
Be aware that in some circumstances (e.g., where the program
specifies an ELF interpreter other than
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
$ 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.
Print the version number of ldd.
Print all information, including, for example, symbol versioning information.
Print unused direct dependencies. (Since glibc 2.3.4.)
Perform relocations and report any missing objects (ELF only).
Perform relocations for both data objects and functions, and report any missing objects or functions (ELF only).
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.
This page is part of release 5.10 of the Linux
project. A description of the project, information about reporting bugs,
and the latest version of this page, can be found at