1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
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3 | <!ENTITY % general-entities SYSTEM "../general.ent">
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4 | %general-entities;
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5 | ]>
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6 | <sect1 id="ch-system-flex" xreflabel="Flex">
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7 | <title>Flex-&flex-version;</title>
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8 | <?dbhtml filename="flex.html"?>
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9 |
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10 | <indexterm zone="ch-system-flex"><primary sortas="a-Flex">Flex</primary></indexterm>
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11 |
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12 | <para>The Flex package contains a utility for generating programs that
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13 | recognize patterns in text.</para>
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14 |
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15 | <screen>&buildtime; 0.1 SBU
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16 | &diskspace; 3.4 MB</screen>
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17 |
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18 | <para>Flex installation depends on: Bash, Binutils, Bison, Coreutils, Diffutils,
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19 | GCC, Gettext, Glibc, Grep, M4, Make, Sed.</para>
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20 |
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21 |
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22 |
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23 | <sect2>
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24 | <title>Installation of Flex</title>
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25 |
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26 | <para>Prepare Flex for compilation:</para>
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27 |
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28 | <screen><userinput>./configure --prefix=/usr</userinput></screen>
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29 |
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30 | <para>Compile the package:</para>
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31 |
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32 | <screen><userinput>make</userinput></screen>
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33 |
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34 | <para>To test the results, issue:
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35 | <userinput>make bigcheck</userinput>.</para>
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36 |
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37 | <para>Now install the package:</para>
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38 |
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39 | <screen><userinput>make install</userinput></screen>
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40 |
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41 | <para>There are some packages that expect to find the <emphasis>lex</emphasis>
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42 | library in <filename>/usr/lib</filename>. Create a symlink to account for
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43 | this:</para>
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44 |
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45 | <screen><userinput>ln -s libfl.a /usr/lib/libl.a</userinput></screen>
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46 |
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47 | <para>A few programs don't know about <command>flex</command> yet and try
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48 | to run its predecessor <command>lex</command>. To support those programs,
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49 | create a wrapper script named <filename>lex</filename> that calls
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50 | <command>flex</command> in <emphasis>lex</emphasis> emulation mode:</para>
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51 |
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52 | <screen><userinput>cat > /usr/bin/lex << "EOF"</userinput>
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53 | #!/bin/sh
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54 | # Begin /usr/bin/lex
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55 |
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56 | exec /usr/bin/flex -l "$@"
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57 |
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58 | # End /usr/bin/lex
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59 | <userinput>EOF
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60 | chmod 755 /usr/bin/lex</userinput></screen>
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61 |
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62 | </sect2>
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63 |
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64 |
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65 | <sect2 id="contents-flex"><title>Contents of Flex</title>
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66 |
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67 | <para><emphasis>Installed programs</emphasis>: flex, flex++ (link to flex)
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68 | and lex</para>
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69 |
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70 | <para><emphasis>Installed library</emphasis>: libfl.a</para>
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71 |
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72 | </sect2>
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73 |
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74 |
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75 | <sect2><title>Short descriptions</title>
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76 |
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77 | <indexterm zone="ch-system-flex flex"><primary sortas="b-flex">flex</primary></indexterm>
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78 | <para id="flex"><command>flex</command> is a tool for generating programs that
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79 | recognize patterns in text. Pattern recognition is useful in many applications.
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80 | From a set of rules on what to look for, flex makes a program that looks for
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81 | those patterns. The reason to use flex is that it is much easier to specify
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82 | the rules for a pattern-finding program than to write the program.</para>
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83 |
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84 | <indexterm zone="ch-system-flex flex-"><primary sortas="b-flex++">flex++</primary></indexterm>
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85 | <para id="flex-"><command>flex++</command> invokes a version of flex that is used
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86 | exclusively for C++ scanners.</para>
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87 |
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88 | <indexterm zone="ch-system-flex libfl.a"><primary sortas="c-libfl.a">libfl.a</primary></indexterm>
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89 | <para id="libfl.a"><command>libfl.a</command> is the flex library.</para>
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90 |
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91 | </sect2>
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92 |
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93 |
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94 |
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95 | </sect1>
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