[sac-dev] byte order and swapping

[Brian Savage]

I have done a bit of thinking about the byte-order situation and problem 
with using write header.  I can confirm that using read header and write 
header on a sac file in the opposite byte order does not work and 
basically destroys the sac file.  My thought for fixing this bug is as 
follows:

On read:
	Add a variable which tracks if the file needed to be swapped on read or 
read header.

On write header:
	if file not swapped on read:
		write header
	if file was swapped on read:
		swap header and write

On write:
	if file not swapped on read:
		write header and data
	if file was swapped on read:
		swap header and data then write

The above tries to keep code in the same byte order it was read in as.

Any thoughts ?

This of course could be extended to include a preferred byte order per 
user (LittleEndian/BigEndian or Linux/Sun/Mac/Automatic).  However, this 
would most likely require that doing a read header/write header sequence 
on a swapped byte order file would mean that the data would need to be 
read in, swapped, and written out.

Cheers,
Brian