lfs-book-zh_CN/chapter06/strippingagain.xml

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  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../general.ent">
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<sect1 id="ch-system-strippingagain">
  <?dbhtml filename="strippingagain.html"?>

  <title>Stripping Again</title>

  <para>If the intended user is not a programmer and does not plan to do
  any debugging on the system software, the system size can be decreased
  by about 90 MB by removing the debugging symbols from binaries and
  libraries. This causes no inconvenience other than not being able to
  debug the software fully anymore.</para>

  <para>Most people who use the command mentioned below do not
  experience any difficulties. However, it is easy to make a typo and
  render the new system unusable, so before running the
  <command>strip</command> command, it is a good idea to make a
  backup of the LFS system in its current state.</para>

  <para>First back up some libraries that are needed when running regression 
  tests in BLFS packages:</para>

<screen><userinput>save_libs="ld- libatomic libc- libcilkrts ligfortran libgo libgomp"
save_libs="$save_libs libitm libmpx libobjc libpthread libquadmath" 
save_libs="$save_libs libsanitizer libstdc++ libthread_db libvtv"

mkdir -p /var/dbg/lib /var/dbg/usr/lib

for lib in $save_libs
do
    find /usr/lib -name ${lib}*so* -type f -exec cp {} /var/dbg/usr/lib \;
    find /lib     -name ${lib}*so* -type f -exec cp {} /var/dbg/lib     \;
done</userinput></screen>

  <para>Before performing the stripping, take special care to ensure that
  none of the binaries that are about to be stripped are running. If
  unsure whether the user entered chroot with the command given in
  <xref linkend="ch-system-chroot" role=","/> first exit from
  chroot:</para>

<screen role="nodump"><userinput>logout</userinput></screen>

  <para>Then reenter it with:</para>

<screen role="nodump"><userinput>chroot $LFS /tools/bin/env -i            \
    HOME=/root TERM=$TERM PS1='\u:\w\$ ' \
    PATH=/bin:/usr/bin:/sbin:/usr/sbin   \
    /tools/bin/bash --login</userinput></screen>

  <para>Now the binaries and libraries can be safely stripped:</para>

<screen><userinput>/tools/bin/find /usr/lib -type f -name \*.a \
   -exec /tools/bin/strip --strip-debug {} ';'

/tools/bin/find /lib /usr/lib -type f -name \*.so* \
   -exec /tools/bin/strip --strip-unneeded {} ';'

/tools/bin/find /{bin,sbin} /usr/{bin,sbin,libexec} -type f \
    -exec /tools/bin/strip --strip-all {} ';'</userinput></screen>

  <para>A large number of files will be reported as having their file
  format not recognized. These warnings can be safely ignored. These
  warnings indicate that those files are scripts instead of
  binaries.</para>

  <para>If desired, restore the saved libraries with the debug data
  intact.  The files can restored now or just held for later use.  Note
  that several of the files cannot be copied directly after rebooting
  to the new LFS system. Later use requires booting to another system,
  mounting the LFS partition, and then copying the files.</para>

<screen><userinput>cp -av /var/dbg/lib/* /lib
cp -av /var/dbg/usr/lib/* /usr/lib</userinput></screen>

</sect1>