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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | BUGS | SEE ALSO | COLOPHON |
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ldd(1) General Commands 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.
(Before glibc 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.
--version
Print the version number of ldd.
--verbose
-v Print all information, including, for example, symbol
versioning information.
--unused
-u Print unused direct dependencies. (Since glibc 2.3.4.)
--data-relocs
-d Perform relocations and report any missing objects (ELF
only).
--function-relocs
-r 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 the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.9.1 2024-05-02 ldd(1)
Pages that refer to this page: pldd(1), sprof(1), uselib(2), dl_iterate_phdr(3), dlopen(3), babeltrace2-filter.lttng-utils.debug-info(7), rtld-audit(7), vdso(7), ldconfig(8), ld.so(8), prelink(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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