Manpage of LDD

LDD

Section: Linux Programmer's Manual (1)
Updated: 2016-07-17
Index
 

NAME

ldd - print shared object dependencies  

SYNOPSIS

ldd [option]... file...  

DESCRIPTION

lddprints 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, lddinvokes the standard dynamic linker (see ld.so(8)) with the LD_TRACE_LOADED_OBJECTSenvironment 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, ldddisplays the location of the matching object and the (hexadecimal) address at which it is loaded. (The linux-vdsoand ld-linuxshared 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 lddmay 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 neveremploy lddon 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 

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

ldddoes not work on a.out shared libraries.

ldddoes not work with some extremely old a.out programs which were built before lddsupport was added to the compiler releases. If you use lddon 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)


 

Index

NAME
SYNOPSIS
DESCRIPTION
Security
OPTIONS
BUGS
SEE ALSO

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