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byte swapping 32-bit float and weird od results
Post 302317361 by GoDonkeys on Monday 18th of May 2009 08:57:09 PM
05-18-2009
byte swapping 32-bit float and weird od results
I'm attempting to read a file that is composed of complex 32-bit floating point values on Solaris 10 that came from a 64-bit Red Hat computer.
When I first tried reading the file, it looked like there was a byte-swapping problem and after running the od command on the file Solaris and Red Hat computers, I saw that they were indeed swapped (every other byte). So, I wrote a little Java program that would swap every other byte and the result was the at the byte-level, the files were the same on both computers. The following is the result of running 'od -x' on the file, showing the first 32-bits which represent the real portion of the first complex number:
f8a6 be03 cd76 bc99
What's weird is that when I run 'od -f' on both computers to see the 32-bit floating point value, I get different results! On the Red Hat computer I get: -1.288782e-01 and on the Solaris computer I get: -2.7055474e+34
. How can I have the same byte level file yet come up with completely different values when I try to print out the bytes as 32-bit floats?
This is really messing me up trying to write a C++ program to read this file on the Solaris computer. I'm getting the same value in my C++ code as what I see when I run 'od -f' on the Solaris computer. I've tried just about everything that I can think of and haven't been able to get past this.
Does anyone have any idea on what's going on with the od command between the Red Hat and Solaris computers? Any ideas on how to get my C++ code to give me the correct value for the 32-bit float?
When I first tried reading the file, it looked like there was a byte-swapping problem and after running the od command on the file Solaris and Red Hat computers, I saw that they were indeed swapped (every other byte). So, I wrote a little Java program that would swap every other byte and the result was the at the byte-level, the files were the same on both computers. The following is the result of running 'od -x' on the file, showing the first 32-bits which represent the real portion of the first complex number:
f8a6 be03 cd76 bc99
What's weird is that when I run 'od -f' on both computers to see the 32-bit floating point value, I get different results! On the Red Hat computer I get: -1.288782e-01 and on the Solaris computer I get: -2.7055474e+34
. How can I have the same byte level file yet come up with completely different values when I try to print out the bytes as 32-bit floats?This is really messing me up trying to write a C++ program to read this file on the Solaris computer. I'm getting the same value in my C++ code as what I see when I run 'od -f' on the Solaris computer. I've tried just about everything that I can think of and haven't been able to get past this.
Does anyone have any idea on what's going on with the od command between the Red Hat and Solaris computers? Any ideas on how to get my C++ code to give me the correct value for the 32-bit float?
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LEARN ABOUT CENTOS
rhn_check
RHN_CHECK(8) Red Hat, Inc. RHN_CHECK(8) NAME
rhn_check - Check for and execute queued actions on RHN. SYNOPSIS
rhn_check [options] DESCRIPTION
rhn_check is a client program that connects to "Spacewalk Server", "Red Hat Satellite" or "Red Hat Network Classic" and receives queued actions for this particular system. After receiving the actions, rhn_check will then process them, and return the results to Spacewalk. OPTIONS
-v, --verbose Increase the debugging output. --proxy=PROXY Specify an http proxy to use. --proxyUser=PROXYUSER Specify a username to use for an authenticated proxy. This option must be used in conjunction with proxyPassword. --proxyPassword=PROXYPASSWORD Specify a password to use for an authenticated proxy. This option must be used in conjunction with proxyUser. --version Show the program's version number and exit. -h, --help Show a help message and exit. FILES
/etc/sysconfig/rhn/systemid The digital server ID for this machine if the system has been registered onto "Spacewalk Server", "Red Hat Satellite" or "Red Hat Network Classic". This file does not exist otherwise. /etc/sysconfig/rhn/up2date The common configuration file used by RHN client programs. SEE ALSO
rhn_register(8), rhnreg_ks(8), rhnsd(8), rhn-profile-sync(8), rhnplugin(8), up2date(5). AUTHORS
See the AUTHORS file included with this software. This manual page was written by James Bowes <jbowes@redhat.com> BUGS
Report bugs to <http://bugzilla.redhat.com>. COPYRIGHT
Copyright (C) 1999-2010 Red Hat, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU- LAR PURPOSE. Linux 2010 August 30 RHN_CHECK(8)