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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 49] 49.2 bc: Hexadecimal or Binary Conversion </TITLE><METANAME="DC.title"CONTENT="UNIX Power Tools"><METANAME="DC.creator"CONTENT="Jerry Peek, Tim O'Reilly &amp; Mike Loukides"><METANAME="DC.publisher"CONTENT="O'Reilly &amp; Associates, Inc."><METANAME="DC.date"CONTENT="1998-08-04T21:56:40Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-260-3"SCHEME="ISBN"><METANAME="DC.language"CONTENT="en-US"><METANAME="generator"CONTENT="Jade 1.1/O'Reilly DocBook 3.0 to HTML 4.0"><LINKREV="made"HREF="mailto:online-books@oreilly.com"TITLE="Online Books Comments"><LINKREL="up"HREF="ch49_01.htm"TITLE="49. Working with Numbers"><LINKREL="prev"HREF="ch49_01.htm"TITLE="49.1 bc: Simple Math at the Shell Prompt "><LINKREL="next"HREF="ch49_03.htm"TITLE="49.3 Gotchas in Base Conversion "></HEAD><BODYBGCOLOR="#FFFFFF"TEXT="#000000"><DIVCLASS="htmlnav"><H1><IMGSRC="gifs/smbanner.gif"ALT="UNIX Power Tools"USEMAP="#srchmap"BORDER="0"></H1><MAPNAME="srchmap"><AREASHAPE="RECT"COORDS="0,0,466,58"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="467,0,514,18"HREF="jobjects/fsearch.htm"ALT="Search this book"></MAP><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch49_01.htm"TITLE="49.1 bc: Simple Math at the Shell Prompt "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 49.1 bc: Simple Math at the Shell Prompt "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 49<BR>Working with Numbers</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch49_03.htm"TITLE="49.3 Gotchas in Base Conversion "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 49.3 Gotchas in Base Conversion "BORDER="0"></A></TD></TR></TABLE>&nbsp;<HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-3921">49.2 bc: Hexadecimal or Binary Conversion </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-58517"></A><ACLASS="indexterm"NAME="AUTOID-58520"></A>One thing that's really handy to know about <EMCLASS="emphasis">bc</EM> is how to use itfor base conversion.</P><PCLASS="para"><ACLASS="indexterm"NAME="UPT-ART-3921-IX-IBASE-COMMAND"></A><ACLASS="indexterm"NAME="UPT-ART-3921-IX-OBASE-COMMAND"></A>By default, <EMCLASS="emphasis">bc</EM> takes its input and prints its output indecimal. However, you can set either the input or the outputto be some other base numbering system&nbsp;- for example,hexadecimal or binary&nbsp;- using the <EMCLASS="emphasis">ibase</EM> and <EMCLASS="emphasis">obase</EM> commands.</P><PCLASS="para">For example, to find the decimal equivalents to ahexadecimal number, set <EMCLASS="emphasis">ibase</EM> to 16, and leave <EMCLASS="emphasis">obase</EM> alone(i.e., as decimal). Simply type the number (or a series ofnumbers separated by semicolons) you want converted, and pressRETURN.The decimal equivalent will be printed below.(Hexadecimal numbers from A to F must be typed in uppercase,or <EMCLASS="emphasis">bc</EM> will report an error.)For example:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>bcibase=16B6;7F;FFF</B></CODE>1821274095</PRE></BLOCKQUOTE></P><PCLASS="para">Or if you wanted to convert <EMCLASS="emphasis">to</EM> hexadecimal, you'd set<EMCLASS="emphasis">obase</EM> to 16, and leave <EMCLASS="emphasis">ibase</EM> at 10:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>bcobase=16142</B></CODE>8E</PRE></BLOCKQUOTE></P><PCLASS="para">Or, to convert binary to hexadecimal, set <CODECLASS="literal">ibase=2</CODE> and <CODECLASS="literal">obase=16</CODE>(or <CODECLASS="literal">ibase=16</CODE> and <CODECLASS="literal">obase=2</CODE> for the reverse operation):</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>bcobase=16ibase=211010001</B></CODE>D1</PRE></BLOCKQUOTE></P><PCLASS="para">Type CTRL-d to exit <EMCLASS="emphasis">bc</EM>.Be careful to set <EMCLASS="emphasis">obase</EM> before <EMCLASS="emphasis">ibase</EM>,or you will have<SPANCLASS="link">problems (<ACLASS="linkend"HREF="ch49_03.htm"TITLE="Gotchas in Base Conversion ">49.3</A>)</SPAN>.</P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">TOR</SPAN></P></DIV></DIV><DIVCLASS="htmlnav"><P></P><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch49_01.htm"TITLE="49.1 bc: Simple Math at the Shell Prompt "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 49.1 bc: Simple Math at the Shell Prompt "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><ACLASS="book"HREF="index.htm"TITLE="UNIX Power Tools"><IMGSRC="gifs/txthome.gif"SRC="gifs/txthome.gif"ALT="UNIX Power Tools"BORDER="0"></A></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch49_03.htm"TITLE="49.3 Gotchas in Base Conversion "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 49.3 Gotchas in Base Conversion "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">49.1 bc: Simple Math at the Shell Prompt </TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><ACLASS="index"HREF="index/idx_0.htm"TITLE="Book Index"><IMGSRC="gifs/index.gif"SRC="gifs/index.gif"ALT="Book Index"BORDER="0"></A></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172">49.3 Gotchas in Base Conversion </TD></TR></TABLE><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><IMGSRC="gifs/smnavbar.gif"SRC="gifs/smnavbar.gif"USEMAP="#map"BORDER="0"ALT="The UNIX CD Bookshelf Navigation"><MAPNAME="map"><AREASHAPE="RECT"COORDS="0,0,73,21"HREF="../index.htm"ALT="The UNIX CD Bookshelf"><AREASHAPE="RECT"COORDS="74,0,163,21"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="164,0,257,21"HREF="../unixnut/index.htm"ALT="UNIX in a Nutshell"><AREASHAPE="RECT"COORDS="258,0,321,21"HREF="../vi/index.htm"ALT="Learning the vi Editor"><AREASHAPE="RECT"COORDS="322,0,378,21"HREF="../sedawk/index.htm"ALT="sed &amp; awk"><AREASHAPE="RECT"COORDS="379,0,438,21"HREF="../ksh/index.htm"ALT="Learning the Korn Shell"><AREASHAPE="RECT"COORDS="439,0,514,21"HREF="../lrnunix/index.htm"ALT="Learning the UNIX Operating System"></MAP></DIV></BODY></HTML>
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