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<TITLE>Developer.com - Online Reference Library - 0672311739:RED HAT LINUX 2ND EDITION:GNU Project Utilities</TITLE>

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<!-- ISBN=0672311739 //-->

<!-- TITLE=RED HAT LINUX 2ND EDITION //-->

<!-- AUTHOR=DAVID PITTS ET AL //-->

<!-- PUBLISHER=MACMILLAN //-->

<!-- IMPRINT=SAMS PUBLISHING //-->

<!-- PUBLICATION DATE=1998 //-->

<!-- CHAPTER=17 //-->

<!-- PAGES=0351-0372 //-->

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<a href="0368-0370.html">Previous</A> | <a href="../ewtoc.html">Table of Contents</A> | <a href="../ch18/0373-0376.html">Next</A>

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<A NAME="PAGENUM-371"><P>Page 371</P></A>





<TABLE WIDTH="360">

<TR><TD>

blank

</TD><TD>

Horizontal whitespace

</TD></TR>

<TR><TD>

cntrl

</TD><TD>

Control characters

</TD></TR>

<TR><TD>

digit

</TD><TD>

Digits

</TD></TR>

<TR><TD>

graph

</TD><TD>

Printable characters, not including space

</TD></TR>

<TR><TD>

lower

</TD><TD>

Lowercase letters

</TD></TR>

<TR><TD>

print

</TD><TD>

Printable characters, including space

</TD></TR>

<TR><TD>

punct

</TD><TD>

Punctuation characters

</TD></TR>

<TR><TD>

space

</TD><TD>

Horizontal or vertical whitespace

</TD></TR>

<TR><TD>

upper

</TD><TD>

Uppercase letters

</TD></TR>

<TR><TD>

xdigit

</TD><TD>

Hexadecimal digits

</TD></TR>

</TABLE>















<P>The way to invoke tr with one of these character classes is

`[:classname:]'. To get rid of punctuation, use the

punct class:

</P>





<!-- CODE SNIP //-->

<PRE>

tr `[:punct:]' ` ` &lt; ~/docs/ch16.doc |

tr `A-Z' `a-z' | tr -s ` ` | tr -d `\t\n' |

tr ` ` `\n' | sort | uniq -c | sort -rn

</PRE>

<!-- END CODE SNIP //-->











<P>Here's some of the new output:

</P>





<!-- CODE //-->

<PRE>



405 the

170 to

136 a

134 of

122 and

119 is

 80 files

 74 file

 72 in

 67 or

</PRE>

<!-- END CODE //-->











<P>The numbers are different for some of the words because I have been running the

commands and writing the chapter at the same time.

</P>









<P>I could also have replaced `A-Z' and `a-z' with the

upper and lower classes, but there is no real advantage to using the classes, and the ranges

are much more illustrative of the process.

</P>









<H3><A NAME="ch17_ 20">

Summary

</A></H3>









<P>This chapter covers the four major GNU utilities packages and the major commands in

each of these packages. As you have seen in the various examples, the real power of these

packages lies in their capability to help the user break down complex tasks and solve them quickly.

</P>



<A NAME="PAGENUM-372"><P>Page 372</P></A>













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