What is required to port C/C++/Motif application suite from RedHat Linux ES4 to RedHat Linux ES6

I am about to embark on a project to port our application suite from RedHat ES4 to RedHat ES6. How complex is this? We've had 开发者_C百科differing experiences from version to version in the past and was wondering if there are any specific gotchas in the move to ES6.

It will all depend on what is in your code, how clean it is and how up to date your old Linux is (open-motif 2.2.x vs 2.3.3, gcc version, etc.). If you aren't using any deprecated functionality on ES4, are using suggested coding methods instead of hacks, and your libraries have stable interfaces, then it may just recompile. If not, it will give you a list of some errors that might give you an idea of the complexity, but that will rely mostly on chance and guesswork. If it compiles a lot of files before an error, then probably easy. If it just gives you a lot of errors, then probably hard. You'll get a better idea the more compile jobs run.

From my experience in changing the OS, I wouldn't expect too much help on a prediction. I've moved SUSE Linux code to Ubuntu and Windows with simple recompiles. I had to make a few changes the first couple of times I moved the code between Windows and Linux (well, more than a few first moving from Windows to Linux), but now it's effortless. I have an image slideshow program that I wrote. It started on an old version of Slackware (32-bit), got moved to Gentoo (32 and 64-bit) and Ubuntu (32 and 64-bit). Aside from program improvements, all I've had to do is recompile and maybe install necessary development libraries.

I once ran into a problem with Oracle's OCCI (c++ version of OCI) where my Win32 application would compile and link just fine on Linux (32 or 64 bit), but because of Oracle's failed product support I had to rewrite the database parts using a 3rd-party library for our target platform of Win64. But with a clean design, once I decided to replace the library, it only took 2 days to fix 9 months worth of code.