Bitwise negation Post: 302117646

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Top Forums Shell Programming and Scripting Bitwise negation Post 302117646 by dLloydm on Tuesday 15th of May 2007 08:05:21 PM

05-15-2007

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Bitwise negation

I am taking an online course on Unix scripting. The topic is Unix arithmetic operators and the lesson is Logical and bitwise operations. It is not clear how much storage space Unix uses to represent integers that are typed. Bitwise negation caused me to question how many bits are used to represent numbers.

The course gives an example: ((~ 2#1001)) evaluates to 2#110

This would imply that only 4 bits are used, otherwise I would expect the example to evaluate to 2#11110110 if 8 bits were used an so on.

I do not have access to a Unix OS or this would be easy to check. I don't know if the shell matters, but I would assume BASH since it allows integers.

So, how many bits are use to represent such values? I understand Unix represents everything as strings unless declared as integer such as using typeset -i. Is this the same using something like 2#1111?

Thanks for any help...

dLloydm

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LEARN ABOUT X11R4

macutil

MACUTIL(1)						      General Commands Manual							MACUTIL(1)

NAME

       macutil - A package that deals with MacIntosh files on a Unix system

DESCRIPTION

       macutil	is  a package that contains a number of utilities that deal with MacIntosh files on a Unix system.  It contains the following pro-
       grams:

       binhex Convert files to BinHex 4.0 compatible hexified form.

       frommac
	      Receives files from the MacIntosh on the Unix system.

       hexbin Convert hexified files to their MacIntosh format.

       macsave
	      Save a series of files from a MacBinary stream as individual files.

       macstream
	      Combine a series of files to a MacBinary stream.

       macunpack
	      Unpack a MacIntosh archive into its constituents.

       tomac  Transmits files from the Unix system to a MacIntosh.

BUGS

       This manual page is hopelessly incomplete!

SEE ALSO

       binhex(1), frommac(1), hexbin(1), macsave(1), macstream(1), macunpack(1), tomac(1)

AUTHOR

       Dik T. Winter, CWI, Amsterdam, The Netherlands (dik@cwi.nl)

3rd Berkeley Distribution					 October 22, 1992							MACUTIL(1)