|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | BUGS | SEE ALSO | COLOPHON |
LDD(1) Linux Programmer's Manual LDD(1)
ldd - print shared object dependencies
ldd [option]... file...
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 is the following:
$ ldd /bin/ls
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). 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.
--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.
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.
pldd(1), sprof(1), ld.so(8), ldconfig(8)
This page is part of release 4.12 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/.
2017-07-13 LDD(1)
Pages that refer to this page: pldd(1), sprof(1), uselib(2), dl_iterate_phdr(3), dlopen(3), rtld-audit(7), vdso(7), ldconfig(8), ld.so(8), prelink(8)