CODEWITHSUNDEEP
c++g++shared-libraries
Rajesh Kumar
Rajesh Kumar

Reputation: 1290

Unable to load shared library : libxerces.so

While running the application developed by other person, getting the following error

./appln: error while loading shared libraries: libxerces-c.so.28: cannot open shared object file: No such file or directory

And if I run ldd command:

# ldd appln
linux-gate.so.1 =>  (0x00e20000)
libdl.so.2 => /lib/libdl.so.2 (0x00a61000)
libxerces-c.so.28 => not found

I already have that libxerces-c.so.28 file in current folder. Please help me how to resolve that error

Upvotes: 0

Views: 5190

Answers (4)

Basile Starynkevitch
Basile Starynkevitch

Reputation: 1

When adding new "local system" libraries (e.g. in /usr/local/lib/) you better add that directory (/usr/local/lib/) once in your /etc/ld.so.conf and you should run ldconfig to update the linker cache (every time you add something inside /usr/local/lib/)

See ldconfig(8), ld.so(8), ldd(1), dlopen(3)

If you want your own libraries, set LD_LIBRARY_PATH to a directory containing them (e.g. $HOME/lib/ and to standard directories, e.g.

 export LD_LIBRARY_PATH=$HOME/lib:/usr/lib:/usr/local/lib

in your ~/.bashrc (but I dislike that confusing practice, and prefer to manage my /usr/local/lib/).

You could also use some -Wl,-rpath argument but I really dislike that also.

Read also Program Library HowTo and Drepper's paper: How To Write Shared Libraries

Upvotes: 2

glezmen
glezmen

Reputation: 554

By default .so files are NOT being searched in the current folder (they should be in /usr/lib, etc). To add the current directory for .so lookup use:

LD_LIBRARY_PATH=`pwd`:$LD_LIBRARY_PATH  ./appln

Upvotes: 2

CB Bailey
CB Bailey

Reputation: 791361

Evidently "the current folder" isn't in the run time search path used by your executable. I'm assuming that you are on linux (linux-gate.so.1).

You need to ensure that "the current" directory is under the search path. You can do this at link time by using the -rpath option to the linker (-R is also accepted) or -Wl,-rpath,<dir> if you are invoking the linker through the compiler front end. This embeds a search path to be used at run time into your program.

Consider how you want the program to be installed, though. There's no point in adding a path that is specific to your development environment. You might want to consider using $ORIGIN or a $ORIGIN relative path which tells the run time linker to look for shared objects in the location containing (or relative to) the executable. You should always avoid adding . to the run time search path; your program shouldn't behave differently depending on the current directory of the process which invokes it.

As a temporary measure you can set the environment variable LD_LIBRARY_PATH to override the embedded and system search paths but it is normally a bad idea to rely on LD_LIBRARY_PATH overrides for a final installation.

Upvotes: 2

Prof. Falken
Prof. Falken

Reputation: 24867

You need to put libxerces-c.so somewhere in the library path. Probably current folder is not searched for libraries. Try putting it in /usr/local/lib

Upvotes: 3

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