LDD(1) Linux Programmer's Manual LDD(1) NAME ldd - print shared object dependencies SYNOPSIS ldd [option]... file... DESCRIPTION ldd prints the shared objects (shared libraries) required by each pro- gram 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 depen- dency, ldd displays the location of the matching object and the (hexa- decimal) 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 arbi- trary code. A safer alternative when dealing with untrusted executa- bles is: $ objdump -p /path/to/program | grep NEEDED 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 4.10 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/. 2016-07-17 LDD(1) |