null character without reason in written files

[Daniel Molina García]

> Daniel,
> if you're still reading, if the version of gfortran you
> currently have has the -fcheck=bounds option, can you try
> to use it?

I did it, but nothing strange was reported.

However, I'm thinking now that nulls could be caused not by the 
compiler but a fail in the cluster where programs were running. (By the 
way, the software used for managing it is HTCondor)

http://research.cs.wisc.edu/htcondor/

In fact, it is not so unusual that something weird happens. Indeed, 
looking for differences in the files with nulls and without them I found 
that root was the owner of some of the files created by my program 
(although, at every case, those files haven't got nulls)

ls -hl for files without nulls:

http://pastebin.com/kq3FD3uR

and for files with nulls (I renamed them for having a .bad extension):

http://pastebin.com/9HA1jWUR

I didn't found any pattern for distinguishing them.

The way I list the files with nulls is

gawk '/\0/{print FILENAME;nextfile}' *.sal

They can be found with

od -tx1 file | less '+/00 00 00'

and also directly with less and emacs, which are shown as ^@.