lfs-book-zh_CN/chapter06/gzip.xml

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  <!ENTITY % general-entities SYSTEM "../general.ent">
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<sect1 id="ch-system-gzip" role="wrap">
<title>Gzip-&gzip-version;</title>
<?dbhtml filename="gzip.html"?>

<indexterm zone="ch-system-gzip"><primary sortas="a-Gzip">Gzip</primary></indexterm>

<sect2 role="package"><title/>
<para>The Gzip package contains programs for compressing and decompressing
files.</para>

<segmentedlist>
<segtitle>&buildtime;</segtitle>
<segtitle>&diskspace;</segtitle>
<seglistitem><seg>0.1 SBU</seg><seg>2.2 MB</seg></seglistitem>
</segmentedlist>

<segmentedlist>
<segtitle>&dependencies;</segtitle>
<seglistitem><seg>Bash, Binutils, Coreutils, Diffutils,
GCC, Glibc, Grep, Make, and Sed</seg></seglistitem>
</segmentedlist>
</sect2>

<sect2 role="installation">
<title>Installation of Gzip</title>

<para>Gzip has 2 known security vulnerabilities.  The following patch
addresses both of them:</para>

<screen><userinput>patch -Np1 -i ../&gzip-security_fix-patch;</userinput></screen>

<para>Prepare Gzip for compilation:</para>

<screen><userinput>./configure --prefix=/usr</userinput></screen>

<para>The <command>gzexe</command> script has the location of the
<command>gzip</command> binary hard-wired into it. Because the
location of the binary is changed later, the following command ensures
that the new location gets placed into the script:</para>

<screen><userinput>sed -i 's@"BINDIR"@/bin@g' gzexe.in</userinput></screen>

<para>Compile the package:</para>

<screen><userinput>make</userinput></screen>

<para>Install the package:</para>

<screen><userinput>make install</userinput></screen>

<para>Move the <command>gzip</command> program to the <filename
class="directory">/bin</filename> directory and create some commonly used
symlinks to it:</para>

<screen><userinput>mv -v /usr/bin/gzip /bin
rm -v /usr/bin/{gunzip,zcat}
ln -sv gzip /bin/gunzip
ln -sv gzip /bin/zcat
ln -sv gzip /bin/compress
ln -sv gunzip /bin/uncompress</userinput></screen>

</sect2>


<sect2 id="contents-gzip" role="content"><title>Contents of Gzip</title>

<segmentedlist>
<segtitle>Installed programs</segtitle>
<seglistitem><seg>compress (link to gzip), gunzip (link to gzip), gzexe,
gzip, uncompress (link to gunzip), zcat (link to gzip), zcmp, zdiff,
zegrep, zfgrep, zforce, zgrep, zless, zmore, and znew</seg></seglistitem>
</segmentedlist>

<variablelist><bridgehead renderas="sect3">Short Descriptions</bridgehead>
<?dbfo list-presentation="list"?>
<?dbhtml list-presentation="table"?>

<varlistentry id="compress">
<term><command>compress</command></term>
<listitem>
<para>Compresses and decompresses files</para>
<indexterm zone="ch-system-gzip compress"><primary sortas="b-compress">compress</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="gunzip">
<term><command>gunzip</command></term>
<listitem>
<para>Decompresses gzipped files</para>
<indexterm zone="ch-system-gzip gunzip"><primary sortas="b-gunzip">gunzip</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="gzexe">
<term><command>gzexe</command></term>
<listitem>
<para>Creates self-decompressing executable files</para>
<indexterm zone="ch-system-gzip gzexe"><primary sortas="b-gzexe">gzexe</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="gzip">
<term><command>gzip</command></term>
<listitem>
<para>Compresses the given files using Lempel-Ziv (LZ77) coding</para>
<indexterm zone="ch-system-gzip gzip"><primary sortas="b-gzip">gzip</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="uncompress">
<term><command>uncompress</command></term>
<listitem>
<para>Decompresses compressed files</para>
<indexterm zone="ch-system-gzip uncompress"><primary sortas="b-uncompress">uncompress</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zcat">
<term><command>zcat</command></term>
<listitem>
<para>Decompresses the given gzipped files to standard output</para>
<indexterm zone="ch-system-gzip zcat"><primary sortas="b-zcat">zcat</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zcmp">
<term><command>zcmp</command></term>
<listitem>
<para>Runs <command>cmp</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zcmp"><primary sortas="b-zcmp">zcmp</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zdiff">
<term><command>zdiff</command></term>
<listitem>
<para>Runs <command>diff</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zdiff"><primary sortas="b-zdiff">zdiff</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zegrep">
<term><command>zegrep</command></term>
<listitem>
<para>Runs <command>egrep</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zegrep"><primary sortas="b-zegrep">zegrep</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zfgrep">
<term><command>zfgrep</command></term>
<listitem>
<para>Runs <command>fgrep</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zfgrep"><primary sortas="b-zfgrep">zfgrep</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zforce">
<term><command>zforce</command></term>
<listitem>
<para>Forces a <filename class="extension">.gz</filename> extension on all given files
that are gzipped files, so that <command>gzip</command> will not compress them again; this can be
useful when file names were truncated during a file transfer</para>
<indexterm zone="ch-system-gzip zforce"><primary sortas="b-zforce">zforce</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zgrep">
<term><command>zgrep</command></term>
<listitem>
<para>Runs <command>grep</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zgrep"><primary sortas="b-zgrep">zgrep</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zless">
<term><command>zless</command></term>
<listitem>
<para>Runs <command>less</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zless"><primary sortas="b-zless">zless</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="zmore">
<term><command>zmore</command></term>
<listitem>
<para>Runs <command>more</command> on gzipped files</para>
<indexterm zone="ch-system-gzip zmore"><primary sortas="b-zmore">zmore</primary></indexterm>
</listitem>
</varlistentry>

<varlistentry id="znew">
<term><command>znew</command></term>
<listitem>
<para>Re-compresses files from <command>compress</command> format to
<command>gzip</command> format&mdash;<filename class="extension">.Z</filename>
to <filename class="extension">.gz</filename></para>
<indexterm zone="ch-system-gzip znew"><primary sortas="b-znew">znew</primary></indexterm>
</listitem>
</varlistentry>
</variablelist>

</sect2>

</sect1>