Re: Proposal for minor mods to evio

["Stephen A. Wood" <saw@jlab.org>]

Vardan Gyurjyan wrote:
> 
> "Edward J. Brash" wrote:
> 
> > Hi Elliot,
> >
> > In the past, I have had some experience dealing with the coda routines running
> > on the alpha.  Under Tru64 Unix, the solution has been to use the "-taso" switch
> > when compiling these routines.  Under AlphaLinux, however, this switch does not
> > exist.  Steve Wood in Hall C developed a workaround, which involves some changes
> > to specifically the byte-swapping routine in evio, due of course to the 64-bit
> > architecture of the alpha.

It's not really that relevant to this discussion, but I thought that I would
list the fairly simple changes I made to evio for Hall C use.

0.  I didn't do anything about byte swapping.  If byte swapping works on the
Alpha, it's not because I thought about it.  Perhaps not all combinations of
reading and writing on various platforms where one of them is AlphaLinux
would work right.

1.  The Alpha change I made was to deal with the fact that the evio routines
generate and use a handle.  This handle is documented and expected to be 32
bits.  But the handle is really a pointer.  For the alpha I gave evio an
internal table that converts the handle into a 64 bit pointer.

2.  For reading, evopen impliments an ftp like syntax.  If you give evopen
the filename "-", then it reads the coda data from standard input.  If the
filename starts with "|", it interprets the rest of the "filename" as a
command which it executes, piping the output into evread.

3.  When evopen opens a file to read, it checks if it is a gzipped file.  If
it is, it automatically gunzip's it.

4.  For writing, the ftp like syntax is implimented.  evwrite can write to
standard output, or pipe it's output through a command.

						Steve


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Stephen A. Wood      Jefferson Laboratory (formerly CEBAF)
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