---
title: "Copying Shared Library Dependencies"
description: "Shared library dependenices can be easily listed with the help of ldd– list dynamic dependencies of executable files or."
url: "https://h3manth.com/scribe/copying-shared-library-dependencies/"
canonical_url: "https://h3manth.com/scribe/copying-shared-library-dependencies/"
markdown_url: "https://h3manth.com/scribe/blog/copying-shared-library-dependencies.md"
publishDate: "2010-10-04T00:00:00.000Z"
author: "Hemanth HM"
category: "linux"
tags: ["bash","linux"]
word_count: 395
reading_time_minutes: 2
x_markdown_tokens: 897
content_signal: "ai-train=yes, search=yes, ai-input=yes"
---

# Copying Shared Library Dependencies

> Shared library dependenices can be easily listed with the help of ldd– list dynamic dependencies of executable files or.

### I call it cpld a simple utility for copying shared library dependencies to a given folder

Shared library dependenices can be easily listed with the help of ldd– list dynamic dependencies of executable files or shared objects.

**Clues in the ldd source:**

ldd is a very simple utility, that prints the shared libraries required by each program or shared library specified on the command line.

In the ldd source code, there is a line with a comment /_ld.so magic_ /
    
    
    setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1);
    

**Lets see an example:**
    
    
    $ LD_TRACE_LOADED_OBJECTS=1 /bin/bash
        linux-vdso.so.1 =>  (0x00007fff11bff000)
        libncurses.so.5 => /lib/libncurses.so.5 (0x00007f8bfcab0000)
        libdl.so.2 => /lib/libdl.so.2 (0x00007f8bfc8ac000)
        libc.so.6 => /lib/libc.so.6 (0x00007f8bfc529000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f8bfccf3000)
    $ ldd /bin/bash
        linux-vdso.so.1 =>  (0x00007fffe1dff000)
        libncurses.so.5 => /lib/libncurses.so.5 (0x00007fc92daf3000)
        libdl.so.2 => /lib/libdl.so.2 (0x00007fc92d8ef000)
        libc.so.6 => /lib/libc.so.6 (0x00007fc92d56b000)
        /lib64/ld-linux-x86-64.so.2 (0x00007fc92dd5a000)
    

So, the outputs are the same, indeed ldd uses /lib/ld.so with LD_TRACE_LOADED_OBJECTS evn set.

When working will virtual environment for an evalbot there was repeated use of ldd and fixing binaries, so this made me to write a small utility to do the job easy, the code is as below:
    
    
    #!/bin/bash 
    # Author : Hemanth.HM
    # Email : hemanth[dot]hm[at]gmail[dot]com
    # License : GNU GPLv3
    #
    
    function useage()
    {
        cat << EOU
    Useage: bash $0 <path to the binary> <path to copy the dependencies>
    EOU
    exit 1
    }
    
    #Validate the inputs
    [[ $# < 2 ]] && useage
    
    #Check if the paths are vaild
    [[ ! -e $1 ]] && echo "Not a vaild input $1" && exit 1 
    [[ -d $2 ]] || echo "No such directory $2 creating..."&& mkdir -p "$2"
    
    #Get the library dependencies
    echo "Collecting the shared library dependencies for $1..."
    deps=$(ldd $1 | awk 'BEGIN{ORS=" "}$1\
    ~/^\//{print $1}$3~/^\//{print $3}'\
     | sed 's/,$/\n/')
    echo "Copying the dependencies to $2"
    
    #Copy the deps
    for dep in $deps
    do
        echo "Copying $dep to $2"
        cp "$dep" "$2"
    done
    
    echo "Done!"
    

**Case studies :**
    
    
    $ bash cpld.bash 
    Useage: bash cpld.bash <path to the binary> <path to copy the dependencies>
    
    $ bash cpld.bash /bin/bash
    Useage: bash cpld.bash <path to the binary> <path to copy the dependencies>
    
    $ bash cpld.bash /tmp/tet /tmp/test
    Not a vaild input /tmp/tet
    
    $ bash cpld.bash /bin/bash /tmp/deps
    No such directory /tmp/deps creating...
    Collecting the shared library dependencies for /bin/bash...
    Copying the dependencies to /tmp/deps
    Copying /lib/libncurses.so.5 to /tmp/deps
    Copying /lib/libdl.so.2 to /tmp/deps
    Copying /lib/libc.so.6 to /tmp/deps
    Copying /lib64/ld-linux-x86-64.so.2 to /tmp/deps
    Done!
    

Get the [code](http://github.com/hemanth/futhark/raw/1e74bbf9af4df4baf7f916582370609663319644/cpld.bash)