Why ld library path is bad linux

For example, suppose we need to use the freely available libz in our C program, squash , built from squash. Note, the other libraries are incorporated by default, and are not of interest to us.

The last one would be different on a different type of Sun host. This may not be needed in the future because of new functionality in Solaris 8. In Solaris 8, functionality is added for the administrator to easily add default link locations to a host's environment with the crle 1 command. A big problem with the last two methods is that you need sudo access. In the article they say that you can just 'write' in the binary where to look for shared libraries but I do not know how to do that the -L flag does not seem to be doing it.

Thank you in advance. What the -L option does at link time, the -rpath option does at run time. You would then move the library to a known relative path to the binary. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 7 years, 1 month ago. Active 7 years, 1 month ago.

Viewed 6k times. The linking process looks like this: gcc -o prog prog. He, as a Sun employee at that time - in his sun. His acroread example shows how they can complicate the situation such that even more harm is delivered. Darcy on his Oracle blog. As an alternative he describes the elfedit tool available in Solaris 11 and later Solaris 10 patch levels. You might see unexpected results or a degradation in performance. It is not necessary to set it for OpenCSW binaries.

All of them are built with the -R flag, so each binary itself knows where to look for the shared objects. The title of this article is inspired by the considered harmful meme.

Structured Programming with go to Knuth, In addition to that, some vendors that distribute binary executables and libraries just give bad advice in their install instructions.

For example Oracle, the well-known 'enterprise' DB vendor:. At compile time, the linker ld is usually called by the compiler such that all object files a binary executable or library consists of are linked together and dependent libraries are referenced. Some OS's For example, Linux have a configurable loader. Install scripts should never modify this file! This file should contain only the standard library locations as shipped with the OS. If you must ship binaries that use shared libraries and want to allow your clients to install the program outside a 'standard' location, do one of the following: Ship your binaries as.

Some software packages make you install a symlink from the standard location pointing to the real location. What if you need to have two versions installed? This also typically makes things difficult for network installations, since even though you install an application on a network directory, you need to go around to every computer on the network and make a symlink. Solaris's ld will do this with the -i flag. You can also see this with dump -Lv in Solaris.

There you can can specify a run time path which is also evaluated at run time. Now you can move the installation tree to another location entirely and everything will still work.

We need this in other OS's!