Compilation

Compilation FAQs

How do I compile my old 32-bit code under the new 64-bit environment?

You should be able to recompile your code using the same compiler as you did on the old cluster. However, some compiler options may need to be 'tweaked'. For starters try using as few options as possible. For example, remove optimizations, check and debugging options. Investigate possible data alignment issues. If the code worked before, you shouldn't be too far from a solution. For new public domain codes, the task can be a much larger effort.

Where can I find some C++ info?
There are many internet resources. Try the compiler vendors first. Otherwise try:
C++

I am building software in filesystem /cluster/shared and after I unzip or untar the files, they all get erased the next day. What is wrong?
Files older than 21 days are deleted according to the file cleaning policy. Your downloaded files may have been created some time ago. The downloaded files will have the original time-date stamp. To change all the dates, change to the data directory corresponding to your utln and do:

> cd /cluster/shared/utln

> find . -type f -exec touch '{}' \;
> find . -type d -exec touch '{}' \;

This will change both files and directories from that location recursively.
To optionally change ownership recursively:
> chmod -R 755 *

I installed some java code and when I run it on a compute node, an error about the version not being consistent is generated. How do I find what is being used for java in my environment?

Type the following to see what the environment variable is set to:

echo $CLASSPATH